Drug Safety

, Volume 32, Issue 8, pp 637–647 | Cite as

Serenoa repens (Saw Palmetto)

A Systematic Review of Adverse Events
  • Taofikat B. Agbabiaka
  • Max H. Pittler
  • Barbara Wider
  • Edzard ErnstEmail author
Review Article


Serenoa repens (W. Bartram) Small, also known as saw palmetto, is one of the most widely used herbal preparations for the treatment of lower urinary tract symptoms (LUTS) and benign prostatic hyperplasia (BPH). Although a number of randomized controlled trials (RCTs) and systematic reviews of the efficacy of S. repens for the treatment of LUTS and BPH have been published, no systematic review on its drug interactions or adverse events currently exists. This review assesses all available human safety data of S. repens monopreparations.

Systematic literature searches were conducted from date of inception to February 2008 in five electronic databases; reference lists and our departmental files were checked for further relevant publications. Information was requested from spontaneous reporting schemes of the WHO and national safety bodies. Twenty-four manufacturers/distributors of S. repens preparations and four herbalist organizations were contacted for additional information. No language restrictions were imposed. Only reports of adverse events in humans from monopreparations of S. repens were included. Data from all articles, regardless of study design, reporting adverse events or interactions were independently extracted by the first author and validated by the second.

Forty articles (26 randomized controlled trials, 4 non-randomized controlled trials, 6 uncontrolled trials and 4 case reports/series) were included. They suggest that adverse events associated with the use of S. repens are mild and similar to those with placebo. The most frequently reported adverse events are abdominal pain, diarrhoea, nausea, fatigue, headache, decreased libido and rhinitis. More serious adverse events such as death and cerebral haemorrhage are reported in isolated case reports and data from spontaneous reporting schemes, but causality is questionable. No drug interactions were reported.

Currently available data suggest that S. repens is well tolerated by most users and is not associated with serious adverse events. The majority of adverse events are mild, infrequent and reversible, and include abdominal pain, diarrhoea, nausea and fatigue, headache, decreased libido and rhinitis. We found no evidence for drug interactions with S. repens. However, higher quality reporting of adverse events is essential if safety assessments are to be improved in future.


Benign Prostatic Hyperplasia Lower Urinary Tract Symptom Finasteride Tamsulosin Adverse Event Report 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Edzard Ernst was awarded a grant for a research fellowship by Dr Willmar Schwabe GmbH, Karlsruhe, Germany. Taofikat Bisola Agbabiaka was supported by this research fellowship. None of the other authors have any conflicts of interest that are directly relevant to the content of this review to declare. The authors wish to thank Myeong Soo Lee, PhD, Department of Medical Research, Korea Institute of Oriental Medicine, Daejeon, South Korea, for assistance with retrieving relevant articles.

Supplementary material

40264_2012_32080637_MOESM1_ESM.pdf (176 kb)
Supplementary material, approximately 180 KB.


  1. 1.
    Murray M, Pizzorno J. Encyclopedia of natural medicine. Seattle (WA): John Bastyr University Publishing, 1994Google Scholar
  2. 2.
    Lowe FC, Ku JC. Phytotherapy in treatment of benign prostatic hyperplasia: a critical review. Urology 1996; 48: 12–20PubMedCrossRefGoogle Scholar
  3. 3.
    Wilt TJ, Ishani A, Stark G. Saw palmetto extracts for treatment of benign prostatic hyperplasia: a systematic review. JAMA 1998; 280: 1604–9PubMedCrossRefGoogle Scholar
  4. 4.
    Irwin DE, Milsom I, Hunskaar S, et al. Population-based survey of urinary incontinence, overactive bladder, and other lower urinary tract symptoms in five countries: results of the EPIC study. Eur Urol 2006; 50: 1306–14PubMedCrossRefGoogle Scholar
  5. 5.
    Kupelian V, Wei JT, O’Leary MP, et al. Prevalence of lower urinary tract symptoms and effect on quality of life in a racially and ethnically diverse random sample: the Boston Area Community Health (BACH) survey. Arch Intern Med 2006; 166: 2381–7PubMedCrossRefGoogle Scholar
  6. 6.
    Gerber GS, Kuznetsov D, Johnson BC, et al. Randomized, double-blind, placebo-controlled trial of saw palmetto in men with lower urinary tract symptoms. Urology 2001; 58: 960–4PubMedCrossRefGoogle Scholar
  7. 7.
    Vallancien G, Pariente P. Treatment of lower urinary tract symptoms suggestive of benign prostatic obstruction in real life practice in France. Prostate Cancer Prostatic Dis 2001; 4: 124–31PubMedCrossRefGoogle Scholar
  8. 8.
    Blumenthal M, Busse W, Hall T, editors. The complete German Commission E monographs: therapeutic guide to herbal medicines. Newton (MA): Integrative Medicine Communications, 1998Google Scholar
  9. 9.
    Di Silverio F, D’Eramo G, Lubrano C, et al. Evidence that Serenoa repens extract displays an antiestrogenic activity in prostatic tissue of benign prostatic hypertrophy patients. Eur Urol 1992; 21: 309–14PubMedGoogle Scholar
  10. 10.
    Boyle P, Robertson C, Lowe F, et al. Meta-analysis of clinical trials of permixon in the treatment of symptomaticbenign prostatic hyperplasia. Urology 2000; 55: 533–9PubMedCrossRefGoogle Scholar
  11. 11.
    Champault G, Bonnard AM, Cauquil J, et al. Medical treatment of prostatic adenoma. Controlled trial: PA 109 vs placebo in 110 patients. Ann Urol 1984; 18: 407–10Google Scholar
  12. 12.
    Marks LS. 5α reductase: history and clinical importance. Rev Urol 2004; Suppl. 9: S11–21Google Scholar
  13. 13.
    Habib FK, Wyllie MG. Not all brands are created equal: a comparison of selected components of different brands of Serenoa repens extract. Prostate Cancer Prostatic Dis 2004; 7: 195–200PubMedCrossRefGoogle Scholar
  14. 14.
    Reynolds JEF, editor. Serenoa repens. Martindale: the extra pharmacopoeia. London: The Royal Pharmaceutical Society, 1996: 1506Google Scholar
  15. 15.
    Sinclair RD, Mallari RS, Tate B. Sensitization to saw palmetto and minoxidil in separate topical extemporaneous treatments for androgenetic alopecia. Australas J Dermatol 2002; 43: 311–2PubMedCrossRefGoogle Scholar
  16. 16.
    Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo assessment of botanical supplementation on human cytochrome P450 phenotypes: Citrus aurantium, Echinacea purpurea, milk thistle, and saw palmetto. Clin Pharmacol Ther 2004; 76: 428–40PubMedCrossRefGoogle Scholar
  17. 17.
    Al-Shukri SH, Deschaseaux P, Kuzmin IV, et al. Early urodynamic effects of the lipido-sterolic extract of Serenoa repens (permixon®) in patients with lower urinary tract symptoms due to benign prostatic hyperplasia. Prostate Cancer Prostatic Dis 2000; 3: 195–9PubMedCrossRefGoogle Scholar
  18. 18.
    Boccafoschi C, Annoscia S. Serenoa repens extract and placebo in prostatic benign hyperplasia: clinical results. Urologia 1983; 50: 1257–68Google Scholar
  19. 19.
    Carraro JC, Raynaud JP, Koch G, et al. Comparison of phytotherapy (permixon) with finasteride in the treatment of benign prostate hyperplasia: a randomized international study of 1,098 patients. Prostate 1996; 29: 231–40PubMedCrossRefGoogle Scholar
  20. 20.
    Champault G, Patel JC, Bonnard AM. A double-blind trial of an extract of the plant Serenoa repens in benign prostatic hyperplasia. Br J Clin Pharmacol 1984; 18: 461–2PubMedCrossRefGoogle Scholar
  21. 21.
    Cukier J, Ducassou J, Le Guillou M, et al. Permixon® versus placebo: résultats d’une étude multicentrique. Comptes Rendus de Therapeut Pharmacol Clin 1985; 4: 15–21Google Scholar
  22. 22.
    Debruyne F, Koch G, Boyle P, et al. Comparison of a phytotherapeutic agent (permixon) with an alpha-blocker (tamsulosin) in the treatment of benign prostatic hyperplasia: a 1-year randomized international study. Prog Urol 2002; 12: 384–92PubMedGoogle Scholar
  23. 23.
    Debruyne F, Boyle P, Calais da Silva F, et al. Evaluation of the clinical benefit of permixon and tamsulosin in severe BPH patients: PERMAL study subset analysis. Prog Urol 2004; 14: 326–31PubMedGoogle Scholar
  24. 24.
    Descotes JL, Rambeaud JJ, Deschaseaux P, et al. Placebo-controlled evaluation of the efficacy and tolerability of permixon® in benign prostatic hyperplasia after exclusion of placebo responders. Clin Drug Investig 1995; 9: 291–7CrossRefGoogle Scholar
  25. 25.
    Mandressi S, Tarallo U, Maggioni A, et al. Medical treatment of benign prostatic hyperplasia: efficacy of the extract of Serenoa repens (permixon®) compared to that of the extract of Pygeum africanum and placebo. Urologia 1983; 50: 752–7Google Scholar
  26. 26.
    Pytel YA, Vinarov A, Lopatkin N, et al. Long-term clinical and biologic effects of the lipidosterolic extract of Serenoa repens in patients with symptomatic benign prostatic hyperplasia. Adv Ther 2002; 19: 297–306PubMedCrossRefGoogle Scholar
  27. 27.
    Reece Smith H, Menon A, Smart CJ, et al. The value of permixon in benign prostatic hypertrophy. Br J Urol 1986; 58: 36–40PubMedCrossRefGoogle Scholar
  28. 28.
    Stepanov VN, Siniakova LA, Sarrazin B, et al. Efficacy and tolerability of the lipidosterolic extract of Serenoa repens (permixon) in benign prostatic hyperplasia: a double-blind comparison of two dosage regimens. Adv Ther 1999; 16: 231–41PubMedGoogle Scholar
  29. 29.
    Strauch G, Perles P, Vergult G, et al. Comparison of finasteride (proscar) and Serenoa repens (permixon) in the inhibition of 5-alpha reductase in healthy male volunteers. Eur Urol 1994; 26: 247–52PubMedGoogle Scholar
  30. 30.
    Tasca A, Barulli M, Cavazzana A, et al. Treatment of obstructive symptomatology caused by prostatic adenoma with an extract of Serenoa repens: double-blind clinical study vs placebo. Minerva Urol Nefrol 1985; 37: 87–91PubMedGoogle Scholar
  31. 31.
    Aliaev IuG, Vinarov AZ, Lokshin KL, et al. Five-year experience in treating patients with prostatic hyperplasia patients with permixone (Serenoa Repens Pierre Fabre Medicament) [in Russian]. Urologia 2002; 1: 23–5Google Scholar
  32. 32.
    Goepel M, Dinh L, Mitchell A, et al. Do saw palmetto extracts block human alpha1-adrenoceptor subtypes in vivo? Prostate 2001; 46: 226–32PubMedCrossRefGoogle Scholar
  33. 33.
    Braeckman J, Denis L, de Leval J, et al. Double-blind, placebo-controlled study of the plant extract Serenoa repens in the treatment of benign hyperplasia of the prostate. Eur J Clin Res 1997; 9: 247–59Google Scholar
  34. 34.
    Braeckman J, Bruhwyler J, Vandekerckhove K, et al. Efficacy and safety of the extract of Serenoa repens in the treatment of benign prostatic hyperplasia: therapeutic equivalence between twice and once daily dosage forms. Phytother Res 1997; 11: 558–63CrossRefGoogle Scholar
  35. 35.
    Redecker KD. Sabal-extrakt WS 1473 bei benigner prostatahyperplasie. Extracta Urologica 1998; 21: 23–5Google Scholar
  36. 36.
    Ziegler H, Holscher A. Efficacy of saw palmetto fruit extract 1473 in patients with alken stage I–II benign prostatic hyperplasia: open multicentre study. Jatros Uro 1998; 14: 34–3Google Scholar
  37. 37.
    Aliaev IuG, Vinarov AZ, Lokshin KL, et al. Efficiency and safety of prostamol-uno in patients with chronic abacterial prostatitis. Urologia 2006; 1: 47–50Google Scholar
  38. 38.
    Breza J, Kliment J, Valansky L, et al. Prostamol uno (alcohol extract of the fruits of Serenoa repens) in the treatment of symptomatic benign prostatic hyperplasia. Lek Obz 2005; 54: 139–44Google Scholar
  39. 39.
    Roveda S, Colombo P. Clinical controlled trial on therapeutical bioequivalence and tolerability of Serenoa repens oral capsules 160mg or rectal capsules 640mg. Arch Med Interna 1994; 46: 61–75Google Scholar
  40. 40.
    Avins AL, Bent S, Staccone S, et al. A detailed safety assessment of a saw palmetto extract. Complement Ther Med 2008; 16(3): 147–54PubMedCrossRefGoogle Scholar
  41. 41.
    Bent S, Kane C, Shinohara K, et al. Saw palmetto for benign prostatic hyperplasia. N Engl J Med 2006; 354: 557–66PubMedCrossRefGoogle Scholar
  42. 42.
    Prager N, Bickett K, French N, et al. Randomized, double-blind, placebo-controlled trial to determine the effectiveness of botanically derived inhibitors of 5-alpha-reductase in the treatment of androgenetic alopecia. J Altern Complement Med 2002; 8: 143–52PubMedCrossRefGoogle Scholar
  43. 43.
    Willetts KE, Clements MS, Champion S, et al. Serenoa repens extract for benign prostate hyperplasia: a randomized controlled trial. BJU Int 2003; 92: 267–70PubMedCrossRefGoogle Scholar
  44. 44.
    Grasso M, Montesano A, Buonaguidi A, et al. Comparative effects of alfuzosin versus Serenoa repens in the treatment of symptomatic benign prostatic hyperplasia. Arch Esp Urol 1995; 48: 97–103PubMedGoogle Scholar
  45. 45.
    Kaplan SA, Volpe MA, Te AE. A prospective, 1-year trial using saw palmetto versus finasteride in the treatment of category III prostatitis/chronic pelvic pain syndrome. J Urol 2004; 171: 284–8PubMedCrossRefGoogle Scholar
  46. 46.
    Adriazola Semino M, Lozano Ortega JL, García Cobo E, et al. Symptomatic treatment of benign hypertrophy of the prostate: comparative study of prazosin and Serenoa repens. Arch Esp Urol 1992; 45: 211–3PubMedGoogle Scholar
  47. 47.
    Comar OB, Di Rienzo A. Mepartricin vs. Serenoa repens: double-blind study in 20 cases of benign prostate hypertrophy. Rivista Italiana di Biologia e Medicina 1986; 6: 122–5Google Scholar
  48. 48.
    Hizli F, Uygur MC. A prospective study of the efficacy of Serenoa repens, tamsulosin, and Serenoa repens plus tamsulosin treatment for patients with benign prostate hyperplasia. Int Urol Nephrol 2007; 39: 879–86PubMedCrossRefGoogle Scholar
  49. 49.
    Cheema P, El-Mefty O, Jazieh AR. Intraoperative haemorrhage associated with the use of extract of saw palmetto herb: a case report and review of literature. J Intern Med 2001; 250: 167–9PubMedCrossRefGoogle Scholar
  50. 50.
    Jibrin I, Erinle A, Saidi A, et al. Saw palmetto-induced pancreatitis. South Med J 2006; 99: 611–2PubMedCrossRefGoogle Scholar
  51. 51.
    Yeu E, Grostern R. Saw palmetto and intraoperative floppyiris syndrome. J Cataract Refract Surg 2007; 33: 927–8PubMedCrossRefGoogle Scholar
  52. 52.
    Giannakopoulos X, Baltogiannis D, Giannakis D, et al. The lipidosterolic extract of Serenoa repens in the treatment of benign prostatic hyperplasia: a comparison of two dosage regimens. Adv Ther 2002; 19: 285–96PubMedCrossRefGoogle Scholar
  53. 53.
    Gerber GS, Zagaja GP, Bales GT, et al. Saw palmetto (Serenoa repens) in men with lower urinary tract symptoms: effects on urodynamic parameters and voiding symptoms. Urology 1998; 51: 1003–7PubMedCrossRefGoogle Scholar
  54. 54.
    Vohra S, Johnston BC, Cramer K, et al. Adverse events associated with pediatric spinal manipulation: a systematic review. Pediatrics 2007; 119: 275–83CrossRefGoogle Scholar
  55. 55.
    Gagnier JJ, Boon H, Rochon P, et al. Recommendations for reporting randomized controlled trials of herbal interventions: explanation and elaboration. J Clin Epidemiol 2006; 59: 1134–49PubMedCrossRefGoogle Scholar

Copyright information

© Adis Data Information BV 2009

Authors and Affiliations

  • Taofikat B. Agbabiaka
    • 1
  • Max H. Pittler
    • 1
    • 2
  • Barbara Wider
    • 1
  • Edzard Ernst
    • 1
    Email author
  1. 1.Complementary Medicine, Peninsula Medical SchoolUniversities of Exeter and PlymouthExeterUnited Kingdom
  2. 2.Institute for Quality and Efficiency in Health Care (IQWiG)CologneGermany

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