Saw Palmetto Supreme [Discontinued] by Gaia Herbs

POSSIBLY EFFECTIVE

• Common cold. Taking echinacea orally while still healthy may help prevent the common cold, but the benefit is probably modest. Echinacea does not seem to have a significant benefit for treating colds that have already developed. Details: Three meta-analyses show a 10% to 58% reduction in the risk of developing a cold when taking various forms of echinacea (17520,17522,95652). A large clinical study shows that adults who use a specific echinacea extract (Echinaforce, A. Vogel Bioforce AG) 0.9 mL three times daily (2400 mg echinacea daily) for 4 months, with an increase to 0.9 mL five times daily (4000 mg echinacea daily) at the first sign of a cold, have 59% fewer cold episodes and 26% fewer days with cold symptoms than those taking placebo (18225). Many smaller studies have shown a non-significant trend toward a prophylactic benefit, but they were likely underpowered to detect a statistically significant difference (3282,6386,17521,95652). Research in adults who are deliberately infected with cold viruses shows that taking echinacea products either does not reduce the incidence of colds, or has a limited effect which is not statistically significant. Products used include E. angustifolia root extract 300 mg three times daily for 7 days before and 5 days after experimental infection (13419), an alcoholic extract of E. purpurea above-ground parts (EchinaGuard, Madaus AG) 2.5 mL three times daily for 7 days before and 7 days after experimental infection (12354), or echinacea 300 mg three times daily for 14 days before and 5 days after experimental infection (8228). These studies are small and have methodological problems. Some small clinical studies have suggested that taking E. purpurea extracts as a tincture or tea to treat the common cold modestly reduces symptom severity and reduces cold duration by a couple of days (6384,10320,10802,12355,14419,20062,111530). Specific products used in these studies include Echinilin by Inovobiologic Inc., and Echinacin and EchinaGuard by Madaus AG (10320,10802,12355,20062). In contrast, higher quality clinical research shows that taking E. purpurea alone or with E. angustifolia does not reduce duration or severity of cold symptoms when compared with placebo (10800,11970,17519,20059). Echinacea has also been evaluated in children. Preliminary clinical research in healthy children 4-12 years old shows that taking a specific E. purpurea product (Echinaforce Junior, A. Vogel) 400 mg three times daily for 4 months reduces the occurrence of cold symptoms, respiratory complications (such as pneumonia and otitis media), and antibiotic prescriptions by 30%, 52%, and 62%, respectively, when compared with vitamin C 50 mg three times daily. Taking echinacea also reduces the average duration of symptoms during respiratory illness by an average of 1.4 days when compared with vitamin C (105719). However, other clinical research in children has found no benefit with a specific E. purpurea product (Echinacin, Madaus AG) (4989,95653).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Anxiety. It is unclear if oral echinacea reduces anxiety. Details: Preliminary clinical research shows that taking a specific E. angustifolia extract (ExtractumPharma ZRT) 40 mg once or twice daily for 7 days reduces anxiety scores on the State-Trait Anxiety Inventory scale when compared with placebo (20064,103233). This extract seems to be more effective in patients with high baseline anxiety scores (103233). A lower dose of 20 mg daily appears to be ineffective (20064). Conversely, a small clinical study in physically healthy adults with mild to moderate anxiety shows that taking the same E. angustifolia extract at doses of 20 or 40 mg twice daily for 6 weeks does not reduce anxiety when compared with placebo (106626).
• Athletic performance. It is unclear if oral echinacea improves athletic performance in healthy, recreationally active males. Details: Preliminary clinical research in healthy, recreationally active males shows that taking echinacea (Puritan's Pride) 2 grams four times daily for 28 days increases serum erythropoietin levels and maximal oxygen consumption (VO2max) during exercise tests (20066). However, two small clinical studies in endurance trained athletes and in non-athletes with high aerobic fitness show that taking E. purpurea 8 or 16 grams once daily for 35 days in combination with other ingredients (Biomedical Research Lab), or taking E. purpurea (Puritan's Pride) 8 grams daily for 42 days, has no effect on erythropoietin levels, VO2max, or aerobic capacity (95651,101593).
• Atopic dermatitis (eczema). Some evidence shows that an echinacea cream may be effective in mild disease, but it has not been compared to conventional treatments such as corticosteroids. Details: Preliminary clinical research in patients with mild atopic dermatitis shows that applying a cream containing echinacea (Linola Plus Cream, Dr. August Wolff GmbH & Co) 2-3 times daily for 12 weeks reduces symptoms such as erythema, edema, pruritus, and dryness when compared with a cream containing birch bark extract (Imlan Crème Pur, Birken AG). However, the echinacea product was no different to the comparator cream at the 4- and 8-week assessments, indicating that it might take up to 12 weeks to show benefit (97499).
• Attention deficit-hyperactivity disorder (ADHD). Although there has been interest in using oral echinacea for ADHD, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Burns. Although there has been interest in using topical echinacea for burns, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Chronic fatigue syndrome (CFS). Although there has been interest in using oral echinacea for CFS, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Coronavirus disease 2019 (COVID-19). It is unclear if oral echinacea is beneficial for preventing or treating COVID-19. Details: A moderate-size open-label clinical study tested the effects of echinacea to prevent or treat respiratory viruses. This study of otherwise healthy adults in Bulgaria shows that taking echinacea extract (Echinaforce, A. Vogel AG) 2400 mg daily for cycles of 2, 2, and 1 months, with a 1-week break between each cycle, does not reduce symptomatic respiratory tract infections, including SARS-CoV-2, or respiratory virus detection overall when compared with usual care. However, echinacea extract does reduce the risk of a positive test for coronaviruses or SARS-CoV-2 by 48% and 63%, respectively. In patients who develop a symptomatic respiratory tract infection, this study also shows that taking the same echinacea extract 4000 mg daily for up to 10 days speeds viral clearance compared with usual care when all virus types were analyzed; however, clearance of SARS-CoV-2 was not improved. Echinacea may also reduce the number of days with a fever, but not other symptoms (111174). The validity of this study is limited by lack of blinding. Further, most patients were unvaccinated against COVID-19; it is unclear whether these results can be extrapolated to vaccinated patients.
• Genital herpes. It is unclear if oral echinacea is beneficial for genital herpes in patients with herpes simplex virus (HSV) type 1 or 2. Details: Some clinical research shows that a specific E. purpurea extract (Echinaforce, A. Vogel Bioforce AG) 800 mg orally twice daily for 6 months does not seem to prevent or reduce the frequency or duration of recurrent genital herpes in patients with herpes simplex virus (HSV) type 1 or 2 (7087).
• Gingivitis. Echinacea, in a mouth rinse or periodontal patch, has only been studied in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that using a mouth rinse containing echinacea, gotu kola, and elderberry (HM-302, Izun Pharmaceuticals) 15 mL three times daily for 14 days might prevent worsening of gingivitis when compared with a placebo rinse, but it produces only minimal improvement in symptoms (20069). Applying a periodontal patch containing echinacea, gotu kola, and elderberry (PerioPatch, Izun Pharmaceuticals) either as a single dose, or three times daily for 1 day then once daily for 2 days seems to reduce some measures of inflammation and gingivitis at some time points, but effects lack consistency (20068,20070).
• Herpes labialis (cold sores). Although there has been interest in using topical echinacea for herpes labialis, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• HIV/AIDS. Although there has been interest in using oral echinacea for HIV/AIDS, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Human papillomavirus (HPV). Oral echinacea has only been studied in combination with other ingredients; its benefit when used alone is unclear. Details: Preliminary clinical research shows that taking a specific combination product containing echinacea, andrographis, grapefruit, papaya, pau d'arco, and cat's claw (Immune Act, Erba Vita SpA) three tablets daily for one month reduces the recurrence of anal condylomata in patients following surgical removal. After one month, the recurrence rate was about 4% in the echinacea group compared with 18% in the control group; after 6 months the recurrence rates were about 7% and 27%, respectively (20073). However, poor study methodology limits the validity of these findings.
• Influenza. Limited data suggest that oral echinacea may improve the response to influenza vaccine, and that a combination product containing echinacea may improve rates of recovery from influenza. Details: Preliminary clinical research shows that a taking a specific echinacea product (Monoselect Echinacea, PharmExtracta) 200 mg orally daily for 15 days, then 100 mg daily for 15 days, followed by 100 mg every other day for 60 days, might improve the response to influenza vaccine in people with chronic bronchitis or asthma (18226). Higher quality research is needed to confirm these results. Taking a specific combination product (Echinaforce Hot Drink, A. Vogel Bioforce AG), containing elderberry juice and extracts of E. purpurea above-ground parts and roots, 5 mL five times daily for 3 days, then three times daily for 7 days, improves rates of recovery and influenza-related respiratory complications similarly to oseltamivir 75 mg twice daily for 5 days (95650). However, due to the lack of a placebo group, it is unclear if both treatments were beneficial or if the outcomes represent the natural progression of influenza.
• Insect bite. It is unclear if topical homeopathy with a gel containing echinacea is beneficial for insect bite treatment. Oral echinacea has not been evaluated for this use. Details: Preliminary clinical research shows that using a homeopathic after-bite gel, containing echinacea, marsh Labrador tea, and stinging nettle, on affected areas does not reduce erythema or itching after a mosquito bite when compared with placebo (89235).
• Lichen planus. It is unclear if oral echinacea is beneficial for patients with this condition. Details: A small clinical study in adults with erosive oral lichen planus in Iran shows that taking a specific echinacea extract tablet (Immustim, Goldaru Corp.) 114 mg three times daily for 35 days decreases pain scores, number of lesions, and symptom severity when compared with placebo. However, all patients also used a mouthwash containing betamethasone, diphenhydramine, nystatin, and aluminum-magnesium suspension three times daily (111173).
• Malaria. Although there has been interest in using oral echinacea for malaria, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Migraine headache. Although there has been interest in using oral echinacea for migraine headache, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Otitis media. Oral echinacea does not seem to reduce the rate of recurrence of otitis media in young children, and may actually increase it. Details: Preliminary clinical research shows that taking a specific liquid extract of echinacea fresh roots and dried mature seeds, 0.5 mL three times daily for 3 days at the first sign of a common cold, followed by 0.25 mL three times daily for 7 days, does not prevent otitis media in children 1-5 years of age with a history of recurrent otitis media. In fact, the risk of an episode of otitis media during the 6 month follow-up seemed to increase by 59% in those taking echinacea when compared with placebo (20063).
• Psoriasis. Although there has been interest in using topical echinacea for psoriasis, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Respiratory tract infections. It is unclear if oral echinacea is beneficial for patients with respiratory tract infections. Details: A large clinical study in adults with respiratory tract infections shows that using echinacea spray or taking echinacea lozenges 16,800 mg daily during days 1-3 and 2240-3360 mg daily afterward for up to 10 days does not improve time to recovery, symptom relief, or number of sick days when compared with echinacea tablets or drops at a prophylactic dose of 2400 mg daily for 10 days. However, the higher dose from days 1-3 is associated with faster viral clearance than the prophylactic dose (111540). The validity of these effects is limited by insufficient blinding and a lack of a placebo group.
• Rheumatoid arthritis (RA). Although there has been interest in using oral echinacea for RA, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Tonsillitis. Oral echinacea has been used with azithromycin to reduce relapses of recurrent tonsillitis in children. A throat spray containing echinacea has also been evaluated for tonsillitis-associated sore throat. It is unclear if echinacea is beneficial for either purpose. Details: Preliminary clinical research in children with recurrent tonsillitis shows that adding echinacea suspension, 250 mg root powder per 5 mL, orally 3 times daily for 10 consecutive days per month for 6 months, to azithromycin 10 mg/kg/day for 6 consecutive days per month for 6 months reduces the number of tonsillitis attacks when compared with azithromycin alone (104127). However, the study was not blinded and the number of tonsillitis episodes in both groups was very low. Other preliminary clinical research shows that applying a throat spray containing sage and echinacea whole plant extract every 2 hours up to 10 times daily for up to 5 consecutive days is as effective as a chlorhexidine-lidocaine spray in patients with sore throat due to acute pharyngitis or tonsillitis (20077).
• Tonsillopharyngitis. Oral echinacea has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-sized study in patients aged 12-75 years with acute tonsillopharyngitis shows that taking lozenges containing echinacea extract 800 mg and sage extract 5 times daily for 4 days reduces throat pain and tonsillopharyngitis symptoms when compared to baseline, both acutely within 90 minutes and after 4 days of treatment (111530). The validity of these effects is limited by a lack of a comparator group. It is unclear if these effects are due to echinacea, sage, or the combination.
• Upper respiratory tract infection (URTI). It is unclear if oral echinacea is beneficial for preventing or treating URTIs. Details: A moderate-size open-label clinical study tested the effects of echinacea to prevent or treat respiratory viruses. This study of otherwise healthy adults in Bulgaria shows that taking echinacea extract (Echinaforce, A. Vogel AG) 2400 mg daily for cycles of 2, 2, and 1 months, with a 1-week break between each cycle, does not reduce symptomatic respiratory tract infections, including SARS-CoV-2, or respiratory virus detection overall when compared with usual care. However, echinacea extract does reduce the risk of a positive test for coronaviruses or SARS-CoV-2 by 48% and 63%, respectively. In patients who develop a symptomatic respiratory tract infection, this study also shows that taking the same echinacea extract 4000 mg daily for up to 10 days speeds viral clearance compared with usual care when all virus types were analyzed; however, clearance of SARS-CoV-2 was not improved. Echinacea may also reduce the number of days with a fever, but not other symptoms (111174). The validity of this study is limited by lack of blinding. Further, most patients were unvaccinated against COVID-19; it is unclear whether these results can be extrapolated to vaccinated patients. Another large study in adults with URTIs shows that taking a combination product containing echinacea 1100-2200 mg, zinc, and vitamin C (EZC Pak) daily for 5 days reduces time to recovery by 1.4 days but does not reduce symptom severity when compared with placebo (111512). The validity of these effects is severely limited by multiple instances of selection bias. Additionally, it is unclear if these effects are due to echinacea, other ingredients, or the combination.
• Urinary tract infections (UTIs). Although there has been interest in using oral echinacea for UTIs, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Vaginal candidiasis. Although there has been interest in using oral echinacea for vaginal candidiasis, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Warts. It is unclear if oral echinacea is beneficial for warts when used alone or in combination with other ingredients. Details: Preliminary clinical research shows that taking echinacea 600 mg orally once daily for up to 3 months does not clear common, plantar, or plain cutaneous warts any more effectively than placebo (20080). Other preliminary clinical research shows that taking an oral supplement containing echinacea with methionine, zinc, probiotics, antioxidants and immunostimulants for 6 months, in addition to using conventional topical therapy to treat cutaneous warts, seems to increase the rate of complete remission from 54% to 86% when compared with conventional therapy alone (20071). It is unclear if these effects are due to echinacea, other ingredients, or the combination.
• Water warts. It is unclear if oral echinacea is beneficial for water warts (molluscum contagiosum). Details: In children who have been successfully treated with curettage for molluscum contagiosum, taking a combination of E. angustifolia and E. purpurea orally daily for 2 months is associated with a relapse rate of about 39%, compared with a rate of 68% in a control group that received no oral treatment (104128). The validity of this finding is limited by the lack of a placebo control. E. angustifolia and E. purpurea were taken in doses of 200 mg each in children under 20 kg and 400 mg each in children over 20 kg. More evidence is needed to rate echinacea for these uses.

(Read more about ECHINACEA)

There is insufficient reliable information available about the effectiveness of pipsissewa.

(Read more about PIPSISSEWA)

There is insufficient reliable information available about the effectiveness of poplar.

(Read more about POPLAR)

POSSIBLY EFFECTIVE

• Transurethral resection of the prostate (TURP). Saw palmetto 320 mg daily seems to improve outcomes after TURP surgery in a dose-dependent manner. Details: Clinical research shows that taking saw palmetto (Permixon, Pierre Fabre Medicament) 320 mg daily for 2 months prior to TURP surgery reduces blood loss, the duration of surgery, the development of intraoperative complications, the duration of catheterization, and the length of hospitalization when compared with placebo (73323,73353). Although these studies found benefit, a small study using a lower dose of saw palmetto (Prostagood Mono, Abdi Ibrahim) 160 mg orally once daily for 5 weeks prior to TURP did not find any decrease in the risk of perioperative hemorrhage, or the density of prostate tissue (17202).

POSSIBLY INEFFECTIVE

• Benign prostatic hyperplasia (BPH). Although individual study results are conflicting, the overall body of evidence suggests that saw palmetto does not offer clinically meaningful improvements in BPH-related symptoms. Details: Research on the use of saw palmetto for improving symptoms of BPH is inconsistent and contradictory. To date, the best available evidence addressing the effectiveness of saw palmetto in patients with BPH comes from two high-quality clinical trials sponsored by the National Institutes of Health (NIH). In one of these trials, saw palmetto 160 mg twice daily for one year was ineffective for reducing moderate to severe symptoms of BPH when compared with placebo (14274). In the other trial, taking saw palmetto 320-960 mg daily for 72 weeks did not significantly improve symptoms when compared with placebo (17684). Additionally, meta-analyses of these trials and many of the small trials described below show that taking saw palmetto does not improve BPH-related signs and symptoms or International Prostate Symptom Scores (IPSS) (89441,102835). While several small, low-quality clinical trials and observational studies in patients with BPH suggest that saw palmetto provides some improvement in urinary symptoms, nocturia, urinary flow, and/or residual urine volume when compared with placebo or baseline (6750,6764,6772,73315,73383,73385,73387,89441,96570,110541), other studies show that saw palmetto has no clinically meaningful effect on BPH-related signs and symptoms, including prostate volume (5093,6752,11314,73343,96409). The validity of several of these studies is limited due to the use of per-protocol analyses and/or a lack of placebo control groups. Beyond this, reasons for these discrepant findings are unclear; however, the mixed results may be due to use of different saw palmetto products, varying study methodologies, different patient populations, and varying symptom scoring tools. Additionally, research shows significant variation in the chemical composition of commercially available saw palmetto extracts (17305,89441). Several clinical trials have compared saw palmetto to 5-alpha reductase inhibitors such as finasteride (Proscar) or dutasteride (Avodart). Some small studies suggest that it may be comparable to these medications for relieving BPH symptoms, but with less effect on prostate size or prostate-specific antigen (PSA) levels (6424,96570). It may also be better tolerated, with a positive effect on sexual dysfunction (6424,6763,18215,89441). Additionally, one observational study in patients with BPH has found that taking saw palmetto 320 mg with tamsulosin 0.4 mg daily for 6 months is associated with similar improvements in IPSS and quality of life scores, but also has a lower risk of reduced libido, when compared with tamsulosin plus dutasteride 5 mg or finasteride 0.5 mg daily (110542). Some research has also compared saw palmetto to alpha-adrenergic blockers. Alpha-adrenergic blockers appear to have a faster onset of symptom relief (2732,6750), and saw palmetto might be less effective than the alpha-adrenergic blocker prazosin (Minipress). Although some studies and a meta-analysis suggest it is similarly effective to tamsulosin (Flomax) after 6-12 months of treatment for improving various symptoms of BPH (6775,6776,11243,89441,96570,104804,107483), another meta-analysis found that alpha-blockers were more effective than saw palmetto for these outcomes (102835). Additionally, tamsulosin appears to be more effective than saw palmetto for reducing prostate volume (104802). However, some research suggests that saw palmetto may be better tolerated than tamsulosin (107483). It is unclear if taking saw palmetto with tamsulosin can improve BPH symptoms. Several low-quality studies and a meta-analysis of two of these studies show no additional benefit over using tamsulosin alone (8901,89443,89448,96410). However, one study suggests that a specific saw palmetto extract (Permixon, Pierre Fabre Medicament) 320 mg daily is associated with a 29% decrease in the IPSS when taken alone, compared with a 37% decrease when taken along with tamsulosin 0.4 mg daily for 6 months. Tamsulosin alone was associated with a 31% decrease (104802). Smaller, lower-quality studies of various combinations of saw palmetto with other ingredients have demonstrated some benefit for improving symptoms of BPH, and some have shown equivalence to finasteride, tamsulosin, or tadalafil (Cialis). These ingredients include stinging nettle root (PRO 160/120, Dr. Willmar Schwabe Pharmaceuticals) (6763,17307,73330,89441); cernitin, beta-sitosterol, and vitamin E (11241); selenium and lycopene (Profluss, Konpharma) (90354,97255); pygeum, lycopene, Epilobium parviflorum, and pumpkin seed oil (ProstateEZE Max, Caruso's Natural Health) (92164); and quercetin and beta-sitosterol (Difaprost, Difass International) (96784). Additionally, one study suggests that an enriched form of saw palmetto oil containing 3% beta-sitosterol seems to be more effective than standard saw palmetto oil containing 0.3% beta-sitosterol in reducing IPSS scores (104803).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Androgenic alopecia. It is unclear if oral or topical saw palmetto is beneficial in patients with androgenic alopecia. Details: Clinical research shows that a combination of saw palmetto extract 200 mg plus beta-sitosterol 50 mg taken twice daily for 18-24 months improves subjective scores of hair quantity and quality in males with androgenic alopecia (15550). However, other clinical research shows that taking saw palmetto extract 320 mg daily for 24 months is less effective for improving hair growth in males with androgenic alopecia when compared with finasteride 1 mg daily (89444). Some clinical research shows that saw palmetto lotion applied topically twice daily for 50 weeks improves hair density by 27% in people with androgenic alopecia. However, a 13% improvement was observed in the placebo group, and no between-group comparisons were made (73435). Additionally, a small clinical study in males with androgenic alopecia receiving platelet-rich plasma every 3 weeks shows that applying 1 mL of topical saw palmetto, redensyl, and biotin daily for 12 weeks modestly improves subjective hair loss scores and photographic assessment of hair growth when compared with 1 mL of topical Procapil daily (112176). However, it is unclear if this effect is due to saw palmetto, other ingredients, or the combination.
• Asthma. Although there has been interest in using oral saw palmetto for asthma, there is insufficient reliable information about the clinical effects of saw palmetto for this purpose.
• Chronic bronchitis. Although there has been interest in using oral saw palmetto for chronic bronchitis, there is insufficient reliable information about the clinical effects of saw palmetto for this purpose.
• Chronic prostatitis and chronic pelvic pain syndrome (CP/CPPS). It is unclear if oral saw palmetto is beneficial in patients with CP/CPPS. Details: Preliminary clinical research shows that oral saw palmetto 325 mg daily for one year does not significantly improve symptoms of CP/CPPS when compared with finasteride 5 mg once daily (11354). However, a clinical trial in patients with moderate to severe CP/CPPS shows that taking saw palmetto 160 mg orally twice daily for 12 weeks improves NIH Chronic Prostatitis Index (NIH-CPSI) score after two weeks of treatment in patients with moderate disease and after 4 weeks of treatment in patients with severe disease when compared with placebo. Independent of severity, 73% of patients taking saw palmetto report a 6-point reduction in NIH-CPSI total score, compared to 33% of patients taking placebo (107482). Saw palmetto extract has also been evaluated in combination with other ingredients. A preliminary clinical study shows that taking a combination of saw palmetto extract 320 mg, selenium 50 mcg, and lycopene oil extract 5 mg daily for 8 weeks improves symptoms and peak flow in patients with CP/CPPS when compared with baseline. However, these effects were not observed or were less significant in patients treated with saw palmetto alone (60442).
• Common cold. Although there has been interest in using oral saw palmetto for the common cold, there is insufficient reliable information about the clinical effects of saw palmetto for this purpose.
• Hirsutism. Although there has been interest in using oral and topical saw palmetto for hirsutism, there is insufficient reliable information about the clinical effects of saw palmetto for this purpose.
• Non-neurogenic lower urinary tract symptoms (LUTS). It is unclear if oral saw palmetto is beneficial in females with non-neurogenic LUTS. Details: A small clinical study in elderly Japanese females with LUTS shows that taking saw palmetto extract 320 mg daily for 12 weeks reduces daytime urinary frequency and might improve nocturia, but it does not seem to reduce urinary urgency, incontinence, straining, bladder pain, or urethral pain when compared with placebo (110540).
• Prostate cancer. Small preliminary studies suggest that saw palmetto does not reduce prostate cancer risk or symptoms associated with prostate cancer. Details: Population research shows that people who take saw palmetto supplements do not have a lower risk of developing prostate cancer (15217). Preliminary clinical research also shows that taking saw palmetto 960 mg daily before, during, and after radiation treatment for early prostate cancer does not significantly improve lower urinary tract symptoms when compared with placebo (96412).
• Prostatitis. Adding saw palmetto to antibiotic therapy seems to relieve some symptoms of bacterial prostatitis more effectively than antibiotics alone. Details: Preliminary clinical research in patients with bacterial prostatitis shows that taking saw palmetto extract daily for eight weeks, with prulifloxacin 600 mg daily for 15 days, reduces pain and urinary symptoms more than prulifloxacin alone, but the combination does not appear to improve bacterial eradication or sexual dysfunction more than the antibiotic alone (89442). One small clinical study in patients with chronic nonbacterial prostatitis shows that a specific saw palmetto extract (Prostamol Uno, Profluss) 320 mg daily improves symptoms when compared with no treatment (73329). Combinations of saw palmetto with other supplements have also been used with fluoroquinolone antibiotics, typically resulting in symptom improvement when compared with the antibiotic alone. These supplement combinations include saw palmetto, indole-3-carbinol, and epigallocatexin-3-gallate (Indigal Plus) 2 capsules twice daily for 3 months (73355); saw palmetto 160 mg, stinging nettle 120 mg, curcumin 200 mg, and quercetin 100mg (ProstaMEV plus FlogMEV) for 2 weeks (73346); and saw palmetto 320 mg, Bacillus coagulans 200 mg, and arbutin 100 mg (Lactorepens) daily for 30 days (96411).
• Sexual desire. Although there has been interest in using oral saw palmetto for sexual desire, there is insufficient reliable information about the clinical effects of saw palmetto for this purpose.
• Sexual dysfunction. Although there has been interest in using oral saw palmetto for sexual dysfunction, there is insufficient reliable information about the clinical effects of saw palmetto for this purpose. More evidence is needed to rate saw palmetto for these uses.

(Read more about SAW PALMETTO)

POSSIBLY EFFECTIVE

• Diabetes. Oral stinging nettle seems to improve glycemic control in patients with diabetes. Details: A meta-analysis of 8 small heterogeneous clinical trials in adults with type 2 diabetes shows that taking stinging nettle 1.5-10 grams in divided doses daily for 8-12 weeks reduces fasting blood glucose (FBG) by 18 mg/dL when compared with placebo (102865). Glycated hemoglobin (HbA1c) was not improved, but the study durations were not adequate to detect an improvement in this measure. Despite positive results on FBG, taking stinging nettle does not seem to improve insulin secretion or measures of insulin sensitivity (91519,102865,108903). Another meta-analysis of 3 small clinical studies in adults with type 2 diabetes shows that taking stinging nettle reduces HbA1c by about 1.3% when compared with placebo. This analysis also suggests stinging nettle reduces post-prandial blood glucose by about 114 mg/dL; however, this is based on a single study. Stinging nettle did not improve fasting blood glucose or insulin resistance in this analysis (111503). The validity of these findings is limited by the low quality and heterogeneity of included studies, as well as unclear dosing. Furthermore, since most research has been conducted in Iran, it is unknown if these findings are generalizable to other geographic locations. Stinging nettle has also been used in combination with other natural medicines. One small clinical study in adults with type 2 diabetes shows that taking a product containing stinging nettle leaf extract 200 mg, milk thistle 200 mg, and Boswellia serrata gum 200 mg three times daily for 3 months reduces FBP by about 28 mg/dL and HbA1c by about 1.5%, compared with a smaller reduction in the placebo group (96742). It is unclear if this effect is due to stinging nettle, the other ingredients, or the combination.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Allergic rhinitis (hay fever). It is unclear if oral stinging nettle is beneficial for hay fever. Details: Taking stinging nettle leaf extract 300 mg 3-7 times daily at the first sign of hay fever symptoms seems to provide subjective improvement (7035). However, adding stinging nettle to conventional allergy medication might not provide any additional benefit. One small clinical study shows that adding stinging nettle tablets (Urtidin, Barij Essence Pharmaceutical Co.) 150 mg four times daily for 1 month to treatment with loratadine and nasal saline rinses does not improve symptoms of allergic rhinitis when compared with placebo with loratadine and nasal saline rinses (96743).
• Anemia. Although there is interest in using oral stinging nettle for anemia, there is insufficient reliable information about the clinical effects of stinging nettle for this condition.
• Asthma. Although there is interest in using oral stinging nettle for asthma, there is insufficient reliable information about the clinical effects of stinging nettle for this condition.
• Benign prostatic hyperplasia (BPH). It is unclear if oral stinging nettle is beneficial for BPH. Details: A meta-analysis of clinical research, including 5 clinical studies and 1,128 patients with BPH, shows that taking stinging nettle root extract 360-600 mg in divided doses daily for 2-12 months improves peak urinary flow rate and symptom scores while modestly reducing prostate volume when compared with control. However, the validity of these results is limited by significant heterogeneity due to the variability in the products used and the specific endpoints investigated (96744). In the largest clinical trial in the analysis, patients took stinging nettle root extract 120 mg three times daily for 6 months (76406). Stinging nettle has also been evaluated in combination products. Clinical research in patients with BPH shows that taking a specific combination product (PRO 160/120, Dr. Willmar Schwabe Pharmaceuticals) containing a specific extract of stinging nettle root (WS 1031) 120 mg plus a specific extract of saw palmetto fruit (WS 1473) 160 mg twice daily for 24-48 weeks seems to improve urinary tract symptoms when compared with control; the effect may last at least 48 weeks after treatment (15195,15551,76409). However, taking a different combination product does not seem to be beneficial. A small clinical study in patients with BPH shows that taking a product containing stinging nettle root extract 240 mg, saw palmetto, pumpkin seed oil, lemon bioflavonoid, and beta-carotene, three times daily for 6 months, does not improve symptoms of BPH (5093).
• Bleeding. Topical stinging nettle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Some preliminary clinical research shows that applying 4 mL of a specific product (Ankaferd blood stopper, Mefar Ilaç Sanayi A.S) containing alpinia, licorice, thyme, stinging nettle, and common grape vine to the affected area reduces bleeding, but does not improve the time for episiotomy repair, when compared with using saline (31010).
• Gingivitis. Stinging nettle in a mouthwash solution has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with moderate gingival inflammation suggests that using 10 mL of mouthwash solution containing a 1:1:1 mixture of stinging nettle, juniper, and yarrow twice daily for 3 months does not reduce plaque or bleeding when compared with control (76443). It is not clear if this effect is due to stinging nettle, the other ingredients, or the combination.
• Gout. Although there is interest in using oral stinging nettle for gout, there is insufficient reliable information about the clinical effects of stinging nettle for this condition.
• Gulf war syndrome. It is unclear if oral stinging nettle is beneficial for Gulf war syndrome. Details: A very small exploratory clinical trial in males with Gulf war syndrome shows that taking stinging nettle leaf (Nature's Way) 1305 mg in two divided doses daily for 30 days modestly improves symptom severity when compared with placebo (108311). The clinical relevance of this finding is limited by the use of an unvalidated scoring scale. Additionally, it appears that most patients had mild, unspecified symptoms at baseline; it is unclear if stinging nettle is beneficial for moderate to severe symptoms.
• Hyperandrogenism. It is unclear if oral stinging nettle is beneficial in patients with hyperandrogenism. Details: Preliminary clinical research in females with hyperandrogenism shows that taking dried extract of stinging nettle root 300-600 mg daily for approximately 4 months decreases total and free testosterone levels, but not menstrual cycle conditions, oily skin, or acne, when compared with taking spironolactone and cyproterone (91520).
• Insect bite. Oral stinging nettle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that applying a homeopathic after-bite gel, containing stinging nettle, Echinacea, and marsh Labrador tea, on affected areas does not reduce erythema or itching after a mosquito bite when compared with placebo (89235).
• Kidney stones (nephrolithiasis). Although there is interest in using oral stinging nettle for kidney stones, there is insufficient reliable information about the clinical effects of stinging nettle for this condition.
• Myalgia. Although there is interest in using topical stinging nettle for myalgia, there is insufficient reliable information about the clinical effects of stinging nettle for this purpose.
• Osteoarthritis. Small clinical studies suggest that topical stinging nettle may modestly improve pain in patients with osteoarthritis. It is unclear if oral stinging nettle is beneficial. Details: Topically, stinging nettle leaf may have a counterirritant effect which may improve osteoarthritis pain in some patients. A small clinical study in patients ages 45-82 with osteoarthritis of the thumb shows that applying raw stinging nettle leaf to the thumb for 30 seconds daily for 1 week reduces pain and disability when compared with white dead nettle leaf control (12490). However, in another small clinical study in patients with knee osteoarthritis, topical application of raw stinging nettle leaf to the knee for 1 minute daily for 7 days does not seem to be more effective for reducing pain than applying a leaf from a related stingless nettle (76412). Non-raw stinging nettle has also been tried. In a small open-label study, a formulation of stinging nettle extract (Liquid PhytoCaps Nettle Leaf, Gaia Herbs) 13.33% compounded with lipobase oil-in-water emulsion and applied to the affected area twice daily for 2 weeks, modestly improves pain and function in patients with radiologically confirmed osteoarthritis when compared with baseline (76414). The validity of this finding is limited by the lack of a comparator group. Stinging nettle has also been evaluated orally, in combination with other ingredients. A clinical study in adults with knee osteoarthritis shows that taking a specific combination solution (Rosaxan, medAgil Gesundheitsgesellschaft mbH) containing stinging nettle extract 160 mg, rose hip puree 20 grams, devil's claw 108 mg, and vitamin D 200 IU daily for 12 weeks improves symptoms by an additional 28% and pain scores by an additional 33% when compared with placebo (96741). It is unclear if this effect is due to stinging nettle, the other ingredients, or the combination.
• Tinnitus. Oral stinging nettle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with tinnitus shows that taking a specific product containing stinging nettle, tansy, and rose hip (Neurotec, Rose Pharmed), 100 mg orally daily for 3 months does not improve auditory thresholds when compared with placebo. However, the product improved some subjective symptoms scores, such as perceived loudness and severity scores (110512).
• Urinary tract infections (UTIs). Although there is interest in using oral stinging nettle for UTIs, there is insufficient reliable information about the clinical effects of stinging nettle for this condition. More evidence is needed to rate stinging nettle for these uses.

(Read more about STINGING NETTLE)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Common cold. Clinical research shows that taking three tablets of a specific combination product (Esberitox, Schaper & Brümmer GmbH & Co. KG) containing dry extracts of echinacea root, thuja leaf, and wild indigo root three times daily for 7-9 days improves the severity of cold symptoms, general well-being, and overall response rate when compared with placebo in patients experiencing moderate cold symptoms (6392). It is unclear if these effects are due to wild indigo, the other ingredients, or the combination. More evidence is needed to rate thuja for this use.

(Read more about THUJA)

LIKELY SAFE ...when used orally and appropriately, short-term. Various liquid extracts of Echinacea purpurea have been used safely for up to 10 days, including EchinaGuard (Madaus AG) 20 drops every 2 hours for 1 day, then three times daily (10320), or Echinilin (Inovobiologic Inc.) 40 mL in divided doses for 1 day, then 15 mL in divided doses daily thereafter (12355,20062). Other liquid extracts have been used safely for relatively longer periods, including Echinaforce (A. Vogel Bioforce AG) 2.4 grams daily for 4 months or 1.6 grams daily for 6 months (7087,18225), and Echinacin (Madaus AG) 5 mL twice daily for 10 days, or 4 mL twice daily for 8 weeks (3282,10802). Specific solid dosage forms of echinacea that have been used safely for up to 10 days include Echinacea purpurea above-ground parts (EchinaFresh, Enzymatic Therapy) 300 mg daily (11970), and mixtures of Echinacea purpurea and Echinacea angustifolia herb in divided doses of 6 grams to 10.5 grams for 1 day then 3 grams to 5.1 grams daily (10800,17519,20059). A specific Echinacea angustifolia extract (ExtractumPharma ZRT) has also been used with apparent safety at a dose of 40 mg once or twice daily for up to 7 days (20064,103233). An Echinacea purpurea product (Natures Resource) has been used safely at a dose of 1.8 grams daily for 8 weeks (17521), and echinacea (Puritan's Pride) has been used safely at 8 grams daily for 28 days (20066).

POSSIBLY SAFE ...when used topically, short-term. A specific cream (Linola Plus Cream, Dr. August Wolff GmbH & Co.) containing echinacea extract (WO 3260) has been applied to the skin safely 2-3 times daily for up to 12 weeks (97499). There is insufficient reliable evidence about the safety of echinacea when used parenterally.

CHILDREN: POSSIBLY SAFE
when used orally, short-term. Some clinical research shows that an extract of the above-ground parts of Echinacea purpurea (EC31J2, Echinacin Saft, Madaus AG) in a dose of 3.75 mL twice daily (for ages 2 years to 5 years) or 7.5 mL twice daily (for ages 6 years to 11 years) is safe when used for up to 10 days (4989). However, about 7% of children experienced a rash after taking echinacea, which might have been caused by an allergic reaction (4989). There is concern that allergic reactions could be severe in some children. The Medicines and Healthcare Products Regulatory Agency in the United Kingdom recommends against the use of oral echinacea products in children under 12 years of age due to this risk of allergic reaction (18207). In contrast, another clinical study in children 4-12 years old shows that a specific Echinacea purpurea product (Echinaforce Junior, A. Vogel) does not cause allergic or urticarial reactions more frequently than vitamin C (105719).

PREGNANCY: POSSIBLY SAFE
when used orally, short-term. There is preliminary evidence that mothers can safely use echinacea in the form of E. purpurea or E. angustifolia solid dosage forms, 250-1000 mg daily, or tinctures, up to 30 drops daily, for 5 days to 7 days during the first trimester without adversely affecting the fetus (7056,13418,15123). There is insufficient reliable information available about the safety of echinacea when used for longer than 7 days.

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about ECHINACEA)

LIKELY SAFE ...when used in amounts commonly found in foods. Pipsissewa leaf extract has Generally Recognized as Safe (GRAS) status in the US (4912).

POSSIBLY UNSAFE ...when used long-term. Pipsissewa contains hydroquinone. Long-term use might lead to hydroquinone toxicity (18). There is insufficient reliable information available about the safety of topical use of pipsissewa.

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about PIPSISSEWA)

LIKELY SAFE ...when applied topically and appropriately (2,12). There is insufficient reliable information available about the safety of poplar for its other uses.

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about POPLAR)

LIKELY SAFE ...when used orally and appropriately. Saw palmetto has been safely used in clinical studies lasting up to 3 years (2735,6750,6752,6764,6772,6773,11354,14274,15550,17202,17306,17684,73315,73383,73384,73385,73389,89441,96410,96412,110540).

POSSIBLY SAFE ...when used rectally and appropriately. Saw palmetto has been used safely in clinical research at a dose of 640 mg once daily for 30 days (73387). However, the long-term safety of saw palmetto administered rectally is not known.

PREGNANCY AND LACTATION: LIKELY UNSAFE
when used orally. Saw palmetto has hormonal activity (6766); avoid using.

(Read more about SAW PALMETTO)

POSSIBLY SAFE ...when used orally and appropriately. Stinging nettle root 360-600 mg has been used safely for up to 1 year (5093,11230,15195,76406,96744). ...when used topically and appropriately (12490).

PREGNANCY: LIKELY UNSAFE
when used orally due to possible abortifacient and uterine-stimulant effects (4,6,19).

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about STINGING NETTLE)

LIKELY SAFE ...when used orally in amounts commonly found in foods. Thuja that is thujone-free has Generally Recognized As Safe (GRAS) status for use in foods in the US (4912).

POSSIBLY UNSAFE ...when used orally in medicinal amounts. Large doses of thuja have been reported to cause seizures, severe vomiting, organ toxicity, and death in some cases (6002,40888). There is insufficient reliable information available about the safety of thuja when used topically.

PREGNANCY: LIKELY UNSAFE
when used orally due to abortifacient activity (12); avoid using.

LACTATION: LIKELY UNSAFE
when used orally due to toxicity (11); avoid using.

(Read more about THUJA)

CAFFEINE Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Echinacea can increase plasma levels of caffeine by inhibiting its metabolism.  Details Echinacea seems to increase plasma concentrations of caffeine by around 30% (12155). This is likely due to inhibition of cytochrome P450 1A2 (CYP1A2) by echinacea.

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Echinacea might inhibit the metabolism of CYP1A2 and increase plasma levels of some drugs.  Details Echinacea appears to inhibit CYP1A2 enzymes in humans. Additionally, echinacea seems to increase plasma concentrations of caffeine, a CYP1A2 substrate, by around 30% (12155). Theoretically, echinacea might increase levels of other drugs metabolized by CYP1A2.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Echinacea may induce hepatic CYP3A4 and inhibit intestinal CYP3A4. This may increase or decrease levels of drugs metabolized by CYP3A4.  Details Several clinical trials have shown that taking echinacea for up to one month does not significantly affect the metabolism of various CYP3A4 substrates, including midazolam, docetaxel, etravirine, lopinavir-ritonavir, and darunavir-ritonavir (13712,48618,88164,88165). However, other clinical research shows that echinacea may increase the clearance of midazolam, suggesting that echinacea might induce CYP3A4 (48618). The discrepancy is thought to be due to differing effects of echinacea on intestinal versus hepatic CYP3A4 enzymes. Echinacea appears to induce hepatic CYP3A4 but inhibit intestinal CYP3A4 (12155). In some cases, these effects might cancel each other out, but in others, drug levels may be increased or decreased depending on the level of effect at hepatic and intestinal sites. The effect of echinacea on CYP3A4 activity may differ depending on the CYP3A4 substrate (6450,11026,88162,88167).

DARUNAVIR (Prezista) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, echinacea may interfere with the metabolism of darunavir; however, a small clinical study found no effect.  Details Darunavir is metabolized by cytochrome P450 3A4 (CYP3A4) and is administered with the CYP3A4 inhibitor ritonavir to increase its plasma concentrations. Echinacea has variable effects on CYP3A4, but administration of an E. purpurea root extract (Arkocapsulas Echinacea, Arkopharma) 500 mg four times daily for 14 days did not affect darunavir/ritonavir pharmacokinetics in 15 HIV-infected patients (88163,93578).

DOCETAXEL (Taxotere) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, echinacea may interfere with the metabolism of docetaxel; however, a small clinical study found no effect.  Details Docetaxel is metabolized by cytochrome P450 3A4 (CYP3A4). Echinacea has variable effects on CYP3A4, but taking E. purpurea whole plant extract (Echinaforce, A. Vogel Biopharma AG) 20 drops three times daily for 2 weeks did not alter the pharmacokinetics of docetaxel in one clinical study (88164).

ETOPOSIDE (VePesid) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Echinacea may increase levels of etoposide.  Details In one report, concomitant use of etoposide and echinacea was associated with more severe thrombocytopenia than the use of etoposide alone, suggesting inhibition of etoposide metabolism (20082). Etoposide is a cytochrome P450 3A4 (CYP3A4) substrate. Echinacea has variable effects on CYP3A4, but some studies have reported inhibition of the enzyme (6450,11026,12155,88162,88167).

ETRAVIRINE (Intelence) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, echinacea may interfere with the metabolism of etravirine; however, a small clinical study found no effect.  Details Etravirine is metabolized by cytochrome P450 3A4 (CYP3A4). Echinacea has variable effects on CYP3A4, but taking E. purpurea root extract (Arkocapsulas Echinacea, Arkopharma) 500 mg three times daily for 14 days did not alter the pharmacokinetics of etravirine in HIV-infected patients (88165,93578).

IMMUNOSUPPRESSANTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Echinacea has immunostimulant activity which may interfere with immunosuppressant therapy.  Details Theoretically, echinacea may interfere with immunosuppressant therapy because of its immunostimulant activity (3279,6388,6389,12639).

LOPINAVIR/RITONAVIR (Kaletra) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, echinacea may interfere with the metabolism of lopinavir; however, a small clinical study found no effect.  Details Lopinavir is metabolized by cytochrome P450 3A4 (CYP3A4) and is administered with the CYP3A4 inhibitor ritonavir to increase its plasma concentrations. Echinacea has variable effects on CYP3A4, but taking E. purpurea (Echinamide, Natural Factors Nutritional Products, Inc.) 500 mg three times daily for 14 days did not alter the pharmacokinetics of lopinavir/ritonavir in healthy volunteers (48618,93578).

MIDAZOLAM (Versed) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = B Theoretically, echinacea may increase the metabolism of intravenous midazolam.  Details Echinacea induces hepatic CYP3A4 and might decrease plasma levels of midazolam by about 20%, reducing the effectiveness of intravenous midazolam (12155). Echinacea also appears to inhibit intestinal CYP3A4, which could theoretically increase the bioavailability of oral midazolam. This may cancel out the decrease in availability caused by induction of hepatic CYP3A4, such that overall plasma levels after oral administration of midazolam are not affected by echinacea.

WARFARIN (Coumadin) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = B Echinacea seems to increase the clearance of warfarin, although the effect may not be clinically significant.  Details Preliminary clinical research in healthy male volunteers suggests that taking echinacea increases the clearance of the active S-isomer of warfarin after a single dose of warfarin, but there was not a clinically significant effect on the INR (20083).

(Read more about ECHINACEA)

(Read more about PIPSISSEWA)

(Read more about POPLAR)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Saw palmetto might increase the risk of bleeding with anticoagulant or antiplatelet drugs.  Details Saw palmetto is reported to prolong bleeding time (8659). Theoretically, it might increase the risk of bleeding when used concomitantly with anticoagulant or antiplatelet drugs.

CONTRACEPTIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Saw palmetto might reduce the effectiveness of contraceptive drugs.  Details Saw palmetto might have antiestrogenic effects (6766). Theoretically, it might interfere with contraceptive drugs taken concomitantly.

ESTROGENS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Saw palmetto might reduce the effectiveness of estrogens.  Details Saw palmetto might have antiestrogenic effects (6766). Theoretically, it might interfere with estrogens taken concomitantly.

(Read more about SAW PALMETTO)

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, stinging nettle might have additive effects with antidiabetes drugs.  Details Clinical research shows that stinging nettle might decrease blood glucose levels in patients with diabetes (91519,102865).

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, combining stinging nettle with diuretic drugs may have additive effects.  Details Animal research suggests that the above ground parts and roots of stinging nettle may have a diuretic effect (1,4,11,76402).

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, stinging nettle might reduce excretion and increase levels of lithium.  Details Animal research suggests that stinging nettle has diuretic and natriuretic properties, which could alter the excretion of lithium (76402). The dose of lithium might need to be decreased.

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D There is some concern that stinging nettle might decrease the effects of anticoagulant drugs such as warfarin.  Details Stinging nettle contains a significant amount of vitamin K (19). When taken in large quantities, this might interfere with the activity of warfarin.

(Read more about STINGING NETTLE)

(Read more about THUJA)

General ...Orally, echinacea is well tolerated.
Most Common Adverse Effects:
Orally: Abdominal pain, constipation, diarrhea, heartburn, nausea and vomiting, rashes, and stomach upset.
Serious Adverse Effects (Rare):
Orally: Severe allergic reactions and hepatitis have been reported.

Dermatologic ...Itching, urticaria, tingling, and allergic rashes have been reported with various echinacea preparations (8225,12355,17519,20059,20077,101592,111530,111540). In a study of children aged 2-11 years, rash occurred in about 7% of children treated with an extract of the above-ground parts of E. purpurea (EC31J2, Echinacin Saft, Madaus AG), compared with about 3% of those treated with placebo (4989,95652). There is concern that allergic reactions could be severe in some children. The Medicines and Healthcare Products Regulatory Agency in the United Kingdom (UK) recommends against the use of oral echinacea products in children under 12 years of age due to this risk of allergic reaction (18207). However, another study in children 4-12 years old shows that a specific E. purpurea product (Echinaforce Junior, A. Vogel) did not cause allergic or urticarial reactions more frequently than vitamin C (105719).

Gastrointestinal ...Gastrointestinal adverse effects include nausea and vomiting, abdominal pain, stomach upset, heartburn, diarrhea, and constipation (10802,11970,12355,13419,17519,20059,48680,105719,106626). An unpleasant taste, dry mouth, and burning, tingling or numbness of the tongue also occur (11970,12355,17519,20059,20070,20077).

Hematologic ...A 51-year-old female presented with leukopenia after taking echinacea 450 mg three times daily for 2 months, along with ginkgo biloba, multivitamins, and calcium. Her leukocyte count recovered upon stopping these supplements, but dropped again when she restarted echinacea alone about a year later. The problem resolved when echinacea was stopped permanently (48533). A 32-year-old male presented with severe thrombotic thrombocytopenic purpura (TTP) about 2 weeks after using an extract of E. pallida to treat a cold. He required admission to an intensive care unit and extensive plasmapheresis. The authors speculate that immunostimulant effects of echinacea induced or exacerbated the TTP (48572).

Hepatic ...Although uncommon, cases of echinacea-induced hepatitis have been reported. One case report describes acute cholestatic autoimmune hepatitis in a 45-year-old male who had been taking an echinacea root extract 1500 mg daily for about 2 weeks. He presented with significantly elevated liver function tests (LFTs), elevated immunoglobulin G (IgG) levels, and a positive test for anti-smooth muscle antibodies, indicating an autoimmune process. Elevated LFTs and IgG levels returned to normal within one month of stopping echinacea (17518). Another case report describes acute cholestatic hepatitis in a 44-year-old male who had taken echinacea root tablets 600 mg daily for 5 days to treat flu-like symptoms. He presented with elevated LFTs, prothrombin time, and international normalized ratio (INR). His condition gradually improved after stopping echinacea, and his LFTs normalized within 3 months (91528).
Seven cases of hepatitis associated with echinacea use were reported to the Australian Adverse Drug Reactions Advisory Committee between 1979 and 2000, but specific details are lacking (8225).
One case report describes acute liver failure in a 2 year-old child who had been given about 100 mg of echinacea daily for 2 weeks. The patient presented with jaundice, diarrhea, lethargy, anorexia, and significantly elevated LFTs. A liver biopsy showed hepatocyte swelling, spotty necrosis, and inflammatory infiltrate with eosinophils. A full recovery was made over a 2-week period (88166).

Immunologic ...Allergic reactions, including urticaria, runny nose, dyspnea, bronchospasm, acute asthma, angioedema, and anaphylaxis, have been reported with various echinacea preparations (638,1358,8225). Atopic individuals and those sensitive to other members of the Asteraceae family (ragweed, chrysanthemums, marigolds, daisies) seem to be at higher risk for these reactions (1358,8225).
A case report describes a 36-year-old female who presented with muscle weakness, electrolyte abnormalities, renal tubular acidosis, fatigue, and dry mouth and eyes after taking echinacea, kava, and St. John's Wort for 2 weeks., She also had a positive antinuclear antibody (ANA) test, with elevated anti-dsDNA antibodies SSA and SSB. Sjogren syndrome was diagnosed; the authors hypothesize that it may have been triggered by the immunostimulant effects of echinacea (10319). A 55-year-old male with a history of pemphigus vulgaris in remission for about a year experienced a flare of the disease after taking an echinacea supplement for one week. After stopping echinacea, medical treatment resulted in partial control of the disease (12171). Another case report describes a 58-year-old male who presented with marked eosinophilia and elevated immunoglobulin E (IgE) levels while taking an echinacea supplement. He required prednisone therapy until he stopped taking echinacea 3 years later, at which time his eosinophils and IgE normalized (48623). A 41-year-old male experienced four episodes of erythema nodosum, each occurring after he had taken echinacea for early symptoms of influenza. After stopping echinacea, he had no further exacerbations of erythema nodosum, suggesting that it had been triggered by the immunostimulant effects of echinacea (7057).

Musculoskeletal ...Reports of arthralgia and myalgia have been associated with echinacea (13418).

Neurologic/CNS ...Headache has been reported in people taking various echinacea preparations orally (3282,11970,17519,20059,20064). Dizziness has also been reported (3282,8225,11970). In one study using an alcoholic extract of the above-ground parts of E. purpurea (EC31J0, Echinacin, Madaus AG), somnolence and a tendency to aggressiveness were reported (3282).

(Read more about ECHINACEA)

General ...Orally, chronic use may lead to hydroquinone toxicity. Symptoms of hydroquinone toxicity include tinnitus, vomiting, delirium, convulsions, and collapse (11).

Gastrointestinal ...Orally, chronic use may lead to hydroquinone toxicity. Symptoms of toxicity include vomiting (11).

Neurologic/CNS ...Orally, chronic use may lead to hydroquinone toxicity. Symptoms of toxicity include delirium, convulsions, and collapse (11).

Ocular/Otic ...Orally, chronic use may lead to hydroquinone toxicity. Symptoms of toxicity include tinnitus (11).

(Read more about PIPSISSEWA)

General ...Topically, occasional allergic skin reactions can occur with the use of poplar (2).

Immunologic ...Topically, occasional allergic skin reactions can occur with the use of poplar (2). Poplar contains salicin. However, there are no reports of aspirin-type allergic reactions with the use of salicin-rich plants (12).

(Read more about POPLAR)

General ...Orally, saw palmetto is well tolerated and adverse effects are mild, infrequent, and reversible.
Most Common Adverse Effects:
Orally: Abdominal pain, constipation, decreased libido, diarrhea, dizziness, fatigue, headache, nausea, rhinitis, vomiting.

Cardiovascular ...Occasionally, cases of hypertension, postural hypotension, tachycardia, angina pectoris, arrhythmia, extrasystole, angiopathy, myocardial infarction, and congestive heart failure have been reported in patients using saw palmetto orally (6424,6484,6752,6772,17684,73388,89441). One case of severe bradycardia and second degree heart block was reported in a 64 year-old male taking an unknown amount of saw palmetto for a few weeks (96413).

Dermatologic ...A case report describes a 61-year-old male who developed a fixed drug eruption with localized blisters and erosions three days after starting oral saw palmetto. The lesions resolved when saw palmetto was stopped, but recurred when it was reintroduced six months later. Topical corticosteroid treatment was necessary and the patient was left with some residual hyperpigmented patches (104805). A combination of saw palmetto and beta-sitosterol has been associated with a single report of worsening acne (15550).

Endocrine ...Two case reports involving one 11-year-old female undergoing treatment for telogen effluvium and another 10-year-old female undergoing treatment for hirsutism, describe hot flashes and the onset of menarche associated with use of saw palmetto. One of these patients was consuming saw palmetto in a food supplement; the other was taking a supplement containing saw palmetto 320 mg daily (73361,96414). In both cases, the hot flashes resolved following treatment discontinuation. In one case, a rechallenge with saw palmetto caused a recurrence of hot flashes.

Gastrointestinal ...Gastrointestinal complaints such as nausea, vomiting, constipation, diarrhea, gastralgia, and halitosis are the most frequently reported adverse effects associated with saw palmetto (6484,6752,60442,73315,73320,73348,73354,73383,73385,73388,89441). Less often, cases of duodenal ulcer, dyspepsia, or heartburn have been reported (6772,73329,73354). Meteorism (intestinal gas accumulation) has also been reported with saw palmetto, although causality was unclear (60442).

Genitourinary ...Some clinicians are concerned that saw palmetto might cause erectile dysfunction, ejaculatory disturbance, or altered libido because of its potential effects on 5-alpha-reductase. Some preliminary clinical studies have reported sexual dysfunction, particularly ejaculatory dysfunction, erectile dysfunction, and reduced libido, in patients taking saw palmetto (5093,17202,17684,73383,89441). However, most of these patients were previously diagnosed with prostate disorders, so causality is unclear. Additionally, several clinical studies indicate that the occurrence of impotence in males taking saw palmetto is similar to placebo and tamsulosin (Flomax), and significantly less than finasteride (Proscar) (2732,6424,17306,107481). Rarely, cases of testicular pain, vesical tenesmus, and urinary tract infections have been reported in patients using saw palmetto extract orally (73388).

Hematologic ...Saw palmetto might have antiplatelet effects and potentially increase the risk of bleeding in some patients. There is one report of excessive intraoperative bleeding in a patient who took saw palmetto prior to surgery. Bleeding time normalized when saw palmetto was discontinued (8659). Also, one case of cerebral hemorrhage has been reported, but details are not available to determine causality (6772,73348). A case of retroperitoneal hematoma after bilateral inguinal hernia repair is reported in a male patient taking saw palmetto. The patient was discharged after a 3-day hospitalization in stable condition (112177).

Hepatic ...A case report describes a patient who developed acute hepatitis and pancreatitis while taking saw palmetto. Symptoms resolved when saw palmetto was discontinued, and reemerged upon re-challenge (14457). Other cases of acute hepatitis and pancreatitis, with elevated alkaline phosphatase, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and bilirubin have been reported in patients using saw palmetto orally (14457,73350,73351).

Musculoskeletal ...Orally, saw palmetto may cause fatigue, weakness, muscle pain, and back pain, although these adverse events are rare (6424,73388,89441). A case of saw palmetto-related rhabdomyolysis was reported in an 82-year-old male presenting with kidney dysfunction, increased C-reactive protein levels, and elevated serum creatine kinase (73358).

Neurologic/CNS ...Orally, saw palmetto can cause headaches, dizziness, insomnia, and fatigue (6750,6752,6772,11354,60442,73348,73385,73388,89441).

Ocular/Otic ...A case of intraoperative floppy-iris syndrome (IFIS) has been reported in a patient using saw palmetto orally (73340). However, no statistically significant association between saw palmetto and IFIS was found in a case series of 660 patients undergoing cataract surgery (73347).

Pulmonary/Respiratory ...Rhinitis is one of the more commonly reported adverse effects of saw palmetto (73348). One patient taking saw palmetto extract 160 mg twice daily reported "breathlessness" (73388). Two cases of respiratory depression have been reported in patients using saw palmetto extract (Permixon) 320 mg (6772).

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General ...Orally, stinging nettle seems to be generally well tolerated.
Most Common Adverse Effects:
Orally: Constipation, diarrhea.
Topically: Contact with the raw plant causes itching, rash, and stinging.

Dermatologic ...Topically, fresh stinging nettle leaves and stalk can cause localized rash, itching, and stinging (12490,76399,76412,76414,76417,76428,76448,96746). Usually, short exposure to stinging nettle results in a transient urticarial reaction and a stinging sensation which may persist for more than 12 hours (76399,76414,76417,96746). In one report, a patient placed a fresh stinging nettle leaf on the tongue to suck out the sap of the leaf. Severe tongue edema, pain, and urticaria developed within 5 minutes. Symptoms continued for several hours after the leaf was removed (15197). In another case report, a young couple intoxicated with methamphetamine fell and laid in a stinging nettle bush for 20 minutes, after which urticaria and pain continued for 2-3 weeks, and a heightened sensitivity to cold persisted for several months (96746).

Endocrine ...A case of gynecomastia has been reported for a 33-year-old male who consumed stinging nettle tea 2 cups daily for one month prior to symptom onset. The condition subsided one month after discontinuing stinging nettle tea (76410).
There have been two cases of galactorrhea associated with the consumption of stinging nettle for one month (76410,108902). In one case, a 33-year-old female consuming stinging nettle tea showed high levels of estradiol and low levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH). The levels of these hormones normalized 6 weeks after discontinuing stinging nettle tea (76410). In the other case report describing a 30-year-old female self-treating with stinging nettle 500 mg daily, hormone levels were not reported; however, a mammogram showed scattered areas of fibroglandular density and benign-appearing calcifications. This patient had complete resolution of symptoms 1 week after discontinuation of stinging nettle (108902).

Gastrointestinal ...Orally, stinging nettle root can cause gastrointestinal complaints, including diarrhea and constipation (1,7,11230). Stinging nettle above ground parts may cause mild gastrointestinal discomfort when taken on an empty stomach (7035). Stinging nettle juice may cause diarrhea (1). One patient taking a combination product containing stinging nettle root extract and pygeum bark extract (Prostatonin, Pharmaton) experienced continual gastrointestinal pain and hyperperistalsis. It is not clear if this effect was due to stinging nettle or pygeum (70230).

Genitourinary ...There is a case report of decreased ejaculatory volume associated with an herbal blend product containing stinging nettle root extract, saw palmetto extract, pumpkin seed oil extract, lemon bioflavonoid extract, and beta-carotene (5093). It is unclear if this was due to stinging nettle, other ingredients, or the combination.

Hepatic ...A case of idiosyncratic drug-induced liver disease (DILI) is reported in a 36-year-old female who presented with abdominal pain after 1 month of taking an herbal liver detox tea containing stinging nettle and other ingredients. Remarkable laboratory values included elevated liver enzymes, alkaline phosphatase, and total bilirubin. The patient received a loading dose of N-acetylcysteine and was hospitalized for 12 days (112178). However, it is unclear if the adverse effect was due to the stinging nettle, other ingredients, or the combination.

Other ...Orally, stinging nettle root can cause sweating (1,7).

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General ...Orally, large doses of thuja have been reported to cause toxicity involving headache, nervous agitation, seizures, gastric irritation, vomiting, abdominal pain, and diarrhea. Thuja toxicity has also been reported to cause liver damage, renal toxicity, and death in some cases (6002,40888).

Dermatologic ...In one case report, a 5-year-old female presented with a papillary eccrine adenoma. In an effort to avoid excisional biopsy, alternative therapy was sought and an ointment containing thuja was advised to be applied to the lesion. Application of thuja for 6 months resulted in peripheral extension and central necrosis of the lesion, eventually necessitating complete excision of the lesion (106048).

Gastrointestinal ...Orally, large doses of thuja have been reported to cause toxicity involving gastric irritation, vomiting, abdominal pain, and diarrhea (6002,40888).

Hepatic ...Orally, large doses of thuja have been reported to cause toxicity involving liver damage and death (6002,40888). In one case report, a healthy 40-year-old female taking thuja and black cohosh for 1 month presented with 3 days of severe abdominal pain and AST and ALT levels exceeding 5 times the upper limit of normal. Symptoms improved within 5 days of supplement discontinuation and levels normalized within 2 weeks (106047). It is unclear if this reaction was due to thuja, black cohosh, or other factors.

Neurologic/CNS ...Orally, large doses of thuja have been reported to cause toxicity involving nervous agitation, seizures, and death (6002,40888).

Renal ...Orally, large doses of thuja have been reported to cause toxicity involving renal toxicity and death (6002,40888).

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