Latin Name: Serenoa repens [syn. Sabal serrulata]
Pharmacopeial Name: abal fructus
Other Names: abal
Saw palmetto (SP) is a small, low-growing palm tree, native to southeastern North America, particularly Florida. The fruits (berries) were a staple food and medicine of the indigenous Floridians before European contact (Bennett and Hicklin, 1999; Duke, 1985; Hutchens, 1973; Vogel, 1970). The Seminole people of Florida use the fruit for food and the leaf stems to make medicine baskets (Moerman, 1998). They prepared an aqueous infusion of the berries for treatment of stomachache and dysentery (Duke, 1985) at a dosage of 1 teaspoon dried berries to 1 cup boiling water (Hutchens, 1973). Other sources indicate that native Americans used the fruit as a diuretic and sexual tonic (Duke, 1985; Finzelberg, 1999; Hnsel et al., 1994).
Saw palmetto berry was commonly recommended for various prostatic conditions by healthcare professionals in the early part of the twentieth century. It was an official drug, listed in two editions of the United States Pharmacopoeia from 1906 to 1916 and in the National Formulary from 1926 to 1950 (Boyle, 1991), when its use as a therapeutic option for urinary tract disorders by the medical community declined in the United States (Tyler, 1993). The berries were prescribed dispensed in an alcoholic fluidextract by physicians of the American Eclectic system of medicine (Bergner, 1997; Bone, 1998; Felter and Lloyd, 1985). King's American Dispensatory indicated SP's specific uses as follows: "Relaxation of parts, with copious catarrhal discharges; lack of development, or wasting away of testicles, ovaries, or mammae; prostatic irritation, with painful micturition, and dribbling of urine, particularly in the aged; tenderness of the glands, and other parts concerned in reproduction" (Felter and Lloyd, 1985). The dosage range was wide, from 1 to 60 drops, apparently based on individual diagnosis. The Eclectics described SP as the "old man's friend," as a "remedy for prostatic irritation and relaxation of tissue (rather) than for a hypertrophied prostate" (Bone, 1998; Felter and Lloyd, 1985). In the twentieth century, the United States Dispensatory, 23rd edition, indicated its use for the enlarged prostate of old men (Wood and Osol, 1943).
In Europe, phytotherapeutic agents have a long history of use in the treatment of benign prostatic hyperplasia (BPH). French researchers in the 1960s began to examine the chemical composition of the SP berry. A breakthrough was the development of the proprietary lipophilic (fat-soluble portion) extract of SP berries (Permixon®, Pierre Fabre, France). Rich in fatty acids and sterols, lipophilic (also called liposterolic) extracts of SP berries are currently approved by both the French and German governments for treatment of BPH (Brown, 1996; Tyler, 1993).
There are numerous controlled clinical studies that confirm the safe and effective use of SP preparations in treating the symptoms associated with BPH. There is also preliminary evidence suggesting that the herb may reduce prostate enlargement; however, evidence that SP may help prevent the onset of prostate cancer is lacking.
Many of the early clinical studies of SP for BPH were short-term (three months or less), but they did indicate a fairly rapid response to SP. One 28-day study of 110 BPH patients found 320 mg daily was effective in reducing painful urination (dysuria), nighttime urination (nocturia), and retained urine in the bladder. There was also significant improvement in urine flow rate. Forty-seven of the patients were followed for 15 to 30 months and had continued improvement (Champault et al., 1984). Another early double-blind study was conducted on 27 BPH patients between 49 and 81 years old. The authors reported a 43% increase in urine flow rate after only 60 days of treatment with 320 mg of saw palmetto extract daily, compared to 15% in the placebo group. Only one patient complained of gastric disturbances that led to discontinuation of the treatment (Tasca et al., 1985).
In a more recent three-month, multicenter open trial, 505 patients with mild to moderate symptoms of BPH were treated with Prostaserene®, an oral preparation of SP berry, at a daily dosage of 160 mg twice daily (Braeckman, 1994). At the end of the three-month period, 305 patients were available for evaluation. The quality of life score (using the International Prostate Symptom Score (IPSS), urinary flow rates, residual urinary volume, and prostate size showed significant improvement in patients taking SP after only 45 days of treatment. Serum prostate-specific antigen (PSA) concentration was not modified by taking SP, reducing the risk of masking potential prostate cancer. Only 5% of the patients completing the study reported adverse side effects. After 90 days, 88% of the patients and 88% of the physicians considered the therapy successful. This study indicates that the daily dose of 320 mg is not only effective in the reduction of BPH symptoms, but is also relatively low in adverse side effects.
In an open trial, 60 patients suffering from BPH stage I and II were treated with a twice daily dosage of 160 mg SP extract (Prostagutt® mono, Schwabe, Germany) (Redecker, 1998). Maximum urinary flow rate was defined as the main outcome measure. After three months of treatment, a significant improvement of micturition parameters was observed: an increase of 24% urinary flow rate and a reduction of both residual urine and micturition frequency. Patients reported and demonstrated subjective progress as well.
Similarly, an open multicenter trial involving 109 BPH patients treated twice daily for twelve weeks with 160 mg SP extract (Prostagutt® mono), demonstrated statistically significant and also clinically relevant improvements in micturition symptoms (Ziegler and Holscher, 1998).
In a randomized placebo-controlled clinical study conducted on 25 men with BPH given the standard dose of 320 mg per day of a proprietary SP extract (Permixon®), those with SP experienced statistically significant reductions in levels of prostatic dihydrotestosterone (DHT) and epidermal growth factor (EGF) and increased levels of testosterone (Di Silverio et al., 1998). Additionally, these levels were distinct to the periurethral regions: those with the herb had lower DHT and EGF levels in the periurethral zone. This appears to be evidence of the 5-a-reductase-lowering effects of SP and its more specific regionalized effects compared to the conventional drug finasteride (Proscar®) (Strauch et al., 1994).
Controversy regarding the relative efficacy of treatments for the relief of the symptoms of BPH was addressed in a 1996 French trial (Carraro et al., 1996). This six-month, double-blind, randomized equivalence study compared the effects of an SP extract (320 mg Permixon®) with those of a 5-alpha-reductase inhibitor (5 mg finasteride) in 1,098 men with moderate BPH. The IPSS was used as the primary endpoint. The study found that both Permixon® and finasteride decreased the IPSS, improved quality of life, and increased peak urinary flow rate. Finasteride markedly decreased prostate volume and serum PSA levels. The SP extract improved symptoms with little effect on volume and no change in PSA levels, and fared better than finasteride in a sexual function questionnaire and gave rise to less complaints of decreased libido and impotence.
A critical review of phytotherapeutic agents in the treatment of BPH was less positive about the efficacy of SP (Lowe and Ku, 1996), stating that no well-defined mechanism of action had been proposed, evidence for an anti-androgenic or anti-estrogenic effect was conflicting, and there were no clinical data suggesting an effect on 5-alpha-reductase activity. Clinical trials were criticized for being uncontrolled, limiting their value, and the double-blind, controlled studies had limitations in that most were of short duration (none longer than three months). Problems were attributed to the different compositions of the saw palmetto products tested. The study concluded that standardization of the preparations is needed to compare and accurately assess the effect of the different extracts.
A review of various phytomedicines used in prostate therapy in Europe was published by Buck (1996). The author reviewed clinical research on several proprietary extracts of SP (e.g., Permixon®). The article acknowledged the 5-alpha-reductase-inhibiting activity of the saw palmetto preparations, as well as other mechanisms affecting production of DHT, implicated in BPH.
A recent comparative review looked at the effectiveness and safety of phytomedicines and synthetic drugs in the treatment of BPH, with a focus on SP (Bach et al., 1997). In a three-year trial involving 309 men, saw palmetto was associated with a significant increase in urinary flow rate, and a 50% decrease in residual urine volume. In comparison, the drug finasteride showed a 30% decrease in symptom scores over three years, but urine flow improved only slightly, and residual urine volume was almost unchanged (Bach et al., 1997). Further, 10.7% of finasteride patients discontinued treatment because of side effects, compared to only 1.8% taking SP. The authors concluded that in terms of increasing urinary flow rate, the data showed a clear superiority of the SP extract in comparison to the synthetic drugs.
Saw palmetto's therapeutic efficacy and safety has been documented recently in a systematic review and meta-analysis of clinical studies (Wilt et al., 1998). This article carefully reviewed 18 studies conducted in Germany, France, and Italy. The authors searched for all studies available through the Medline database from 19661997, through EMBASE, Phytodok, the Cochrane Library, bibiographies in studies and review articles, and contacts with "relevant authors and drug companies." In all, 18 clinical studies involving 2,939 men were reviewed, in which patients had symptomatic BPH, the medicinal preparation was made of SP alone or with other botanicals, the trials were placebo-controlled, and the trials lasted for at least 30 days. According to the authors, some of the studies did not report results that allowed them to be included in the meta-analysis. They rated the treatment allocation concealment (for the purposes of blinding the studies) adequate in nine studies. Sixteen studies were double-blinded. Study duration ranged from 4 to 48 weeks (mean 9 weeks). Compared to placebo, SP produced lowered urinary tract scores, lower frequency of nocturia, and improvement in peak urine flow. When compared to finasteride, SP users experienced similar benefits but about a 90% lower incidence of adverse effects. Adverse effects were "mild and infrequent" and erectile dysfunction was lower when compared to finasteride, SP being 1.1% compared to finasteride at 4.9%. The authors noted that more research is needed to determine the long-term effectiveness and the ability to prevent complications associated with BPH.
During the period when the Commission E reviewed the scientific literature (19891991), there was no clinical evidence to support claims that SP reduces the size of an enlarged prostate. However, a recent study has detected shrinkage of the epithelial tissue in the transition zone of the gland (Marks and Tyler, 1999). Two review articles (Koch and Biber, 1994; Niederprum et al., 1994) explored the 5-alpha-reductase-inhibiting properties of the free fatty acids in SP berry. This action is critical to the herb's activity with respect to BPH and may explain a mechanism that might be associated with inhibition of prostate cancer.
Saw palmetto berry consists of the ripe, dried fruit of Serenoa repens (Bartram) Small (syn. Sabal serrulata (Michaux) Nuttall ex Schultes) [Fam. Arecaceae] as well as its preparations in effective dosage. The berries contain fatty oil with fatty acids, esters, phytosterols, and polysaccharides.
Chemistry and Pharmacology
The main constituents include carbohydrates (invert sugar, mannitol, high-molecular-weight polysaccharides with galactose, arabinose, and uronic acid), fixed oils (free fatty acids and their glycerides), steroids, flavonoids, resin, pigment, tannin, and volatile oil (Newall et al., 1996). The fruits and seeds are rich in triacylglycerol-containing oil (50% of the fatty acids contain 14 or less carbons) (Bruneton, 1995).
Saw palmetto has been reported to contain diuretic, urinary antiseptic, endocrinological, and anabolic properties (Newall et al., 1996).
The fruit of SP has been shown in vitro to inhibit the 5-alpha-reductase and aromatoase, significant in the development of BPH (Koch and Biber, 1994). A recent animal study has shown anti-exudative and anti-inflammatory effects as well (Ziegler and Holscher, 1998). Additional research to confirm the purported hormonal and anti-inflammatory effects of SP is required.
The Commission E reported antiandrogenic and anti-exudative activity.
The Commission E approved the internal use of saw palmetto berry for urination problems in benign prostatic hyperplasia stages I and II. Traditional uses include chronic or subacute cystitis, catarrh of the genito-urinary tract, testicular atrophy, sex hormone disorders, and, specifically, prostatic enlargement in modern phytotherapy (Newall et al., 1996).
Note:The Commission E monograph states, "This medication relieves only the symptoms associated with an enlarged prostate without reducing the enlargement. Please consult a physician at regular intervals." This statement may be subject to change in light of the new research noted above (Marks and Tyler, 1999); however, additional studies are required to confirm the potential tissue-shrinking activity.
[Ed. note: Stage I of BPH is characterized by increase in frequency of urination, pollakiuria (abnormally frequent urination), nocturia, delayed onset of urination, and weak urinary stream. Stage II is characterized by the beginning of the decompensation of the bladder function accompanied by formation of residual urine and urge to urinate.]
In rare cases, stomach problems.
Use During Pregnancy and Lactation
No restrictions known.
Interactions with Other Drugs
Dosage and Administration
Unless otherwise prescribed: 12 g cut fruit and other equivalent galenical preparations for oral use, or 320 mg lipophilic ingredients extracted with lipophilic solvents (hexane or ethanol 90% v/v).
Fluidextract 1:1 (g/ml): 12 ml, twice daily.
Fluidextract 1:2 (g/ml): 24 ml, twice daily.
Soft native extract 10:114:1 (w/w) (contains approximately 8595% fatty acids): 160 mg, twice daily.
Dry normalized extract 4:1 (w/w) (contains approximately 25% fatty acids): 400 mg, twice daily.
Bach, D, M. Schmitt, L. Ebeling. 1997. Phytopharmaceutical and synthetic agents in the treatment of benign prostatic hyperplasia (BPH). Phytomedicine 3(4):309313.
Bennett, B.C. and J.R. Hicklin. 1998. Uses of Saw Palmetto (Serenoa repens, Arecacea) in Florida. Econ Bot 52(4):381393.
Bergner, P. 1997. Electic Materia Medica: Saw Palmetto. Medical Herbalism 9(3):1, 1617.
Bone, K.1998. Saw PalmettoA Critical Review, Part 2. MediHerb Professional Review 61:14.
Boyle, W. 1991. Official Herbs: Botanical Substances in the United States Pharmacopoeias 18201990. East Palestine, OH: Buckeye Naturopathic Press.
Braeckman, J. 1994. The extract of Serenoa repens in the treatment of benign prostatic hyperplasia: A multicenter open study. Curr Therapeut Res 55:776785.
Brown, D.J. 1996. Herbal Prescriptions for Better Health. Rocklin, CA: Prima Publishing. 167172.
Bruneton, J. 1995. Pharmacognosy, Phytochemistry, Medicinal Plants. Paris: Lavoisier Publishing.
Buck, A.C. 1996. Phytotherapy for the prostate. Br J Urol 78:325336.
Carraro, J.C. et al. 1996. Comparison of phytotherapy (Permixon) with finasteride in the treatment of benign prostate hyperplasia: a randomized international study of 1,098 patients. Prostate 29(4):231240.
Champault, G., A.M. Bonnard, J. Cauquil, J.C. Patel. 1984. [The medical treatment of prostatic adenoma. A controlled study: PA-109 versus placebo in 110 patients] [In French]. Ann Urol (Paris) 18(6):407410.
Di Silverio, F. et al. 1998. Effects of long-term treatment with Serenoa repens (Permixon) on the concentration and regional distribution of androgens and epidermal growth factor in benign prostatic hyperplasia. Prostate 37(2):7783.
Duke, J.A. 1985. Handbook of Medicinal Herbs. Boca Raton: CRC Press.
Felter, H.W. and J.U. Lloyd. 1985. King's American Dispensatory, Vols. 12. Portland, OR: Eclectic Medical Publications [reprint of 1898 original]. 17501752.
Finzelberg's Nachfolger. 1999. Product Information: ProstaFinTM SP Saw Palmetto-Extracts. Andernach: H. Finzelberg's Nachfolger & Co. KG.
Hnsel, R., K. Keller, H. Rimpler, G. Schneider (eds.). 1994. Hagers Handbuch der Pharmazeutischen Praxis, 5th ed. Vol. 6. Berlin-Heidelberg: Springer Verlag. 680687.
Hutchens, A.R. 1973. Indian Herbology of North America. Ontario: Merco. 243244.
Koch, E. and A. Biber. 1994. Pharmacological effects of Sabal and Urtica extracts as a basis for a rational medication of benign prostatic hyperplasia. Urologe 34:38.
Lowe, F.C. and J.C. Ku. 1996. Phytotherapy in treatment of benign prostate hyperplasia: a critical review. Urology 48(1):1220.
Marks, L.S. and V.E. Tyler. 1999. Saw palmetto extract: newest (and oldest) treatment alternative for men with symptomatic benign prostatic hyperplasia. Urology 53(3):457461.
Moerman, D.E. 1998. Native American Ethnobotany. Portland, OR: Timber Press, Inc. 527528.
Newall, C.A., L.A. Anderson, J.D. Phillipson. 1996. Herbal Medicines: A Guide for Health-Care Professionals. London: The Pharmaceutical Press.
Niederprum, H.J., H.U. Schweikert, K.S. Znker. 1994. Testosterone 5-a-reductase inhibition by free fatty acids from Sabal serrulata fruits. Phytomedicine 1:127133.
Redecker, K.D. 1998. Sabal extract WS 1473 in benign prostatic hyperplasia. Extracta Urologica. 21(3):2325.
Strauch, G. et al. 1994. Comparison of finasteride (Proscar) and Serenoa repens (Permixon) in the inhibition of 5-alpha reductase in healthy male volunteers. Eur Urol 26(3):247252.
Tasca, A. et al. 1985. [Treatment of obstructive symptomatology caused by prostatic adenoma with an extract of Serenoa repens: Double-blind clinical study vs. placebo] [In Italian]. Minerva Urol Nefrol 37(1):8791.
Tyler, V.E. 1993. The Honest Herbal, 3rd ed. New York: Pharmaceutical Products Press. 285287.
Vogel, V.J. 1970 American Indian Medicine. Norman, OK: University of Oklahoma Press. 365366.
Wilt, T.J. et al. 1998. Saw palmetto extracts for treatment of benign prostatic hyperplasia: a systematic review. JAMA. 280(18):16041609.
Wood, H.C. and A. Osol. 1943. United States Dispensatory, 23rd ed. Philadelphia, PA: J.B. Lippincott. 971972.
Ziegler, H. and U. Holscher. 1998. Efficacy of saw palmetto fruit special extract WS 1473 in patients with Alken stage III benign prostatic hyperplasiaopen mulitcentre study. Jatros Uro 14(3):3443.
Boccafoschi, C. and S. Annoscia. 1983. Comparison of Serenoa repens extract with placebo by controlled clinical trial in patients with prostatic adenomatosis. Urologia 50:12571268.
Bombardelli, E. and P. Morazzoni. 1997. Serenoa repens (Bartram) J.K. Small. Fitoterapia 68(2):99113.
Braeckman, J., J. Bruhwyler, K. Vandekerckhove, J. Geczy. 1997. 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 11:558563.
Carbin, B.E., B. Larsson, O. Lindahl. 1990. Treatment of benign prostatic hyperplasia with phytosterols. Br J Uro 66(6):639641.
Carilla, E., M. Briley, F. Fauran, C. Sultan, C. Duvilliers. 1984. Binding of Permixon, a new treatment for prostatic benign hyperplasia, to the cytosolic androgen receptor in the rat prostate. J Steroid Biochem 20(1):521523.
Cukier, P. et al. 1985. Permixon versus placebo: Results of a multicenter study. C R Ther Pharmacol Clin 4:1521.
Di Silverio, F. et al. 1992. Evidence that Serenoa Repens extract displays an antiestrogenic activity in prostatic tissue of benign prostatic hypertrophy patients. Eur Urol 21(4):309314.
Di Silverio, F. et al. 1993. Plant extracts in BPH. Minerva Urol Nefrol 45(4):143149.
Emili, E. et al. 1983. Clinical results with a new drug therapy against benign prostatic hypertrophy (Permixon). Urologia 50:10421048.
Gerber, G.S., G.P. Zagaja, G.T. Bales, G.W. Chodak, B.A. Contreras. 1998. Saw Palmetto (Serenoa repens) in men with lower urinary tract symptoms: Effects on urodynamic parameters and voiding symptoms. Urology 51(6):10031007.
Gerber, G.S. et al. 1997. Serenoa repens (saw palmetto) in men with benign prostatic hyperplasia (BPH): Effects on voiding symptoms, urodynamic parameters and serum prostate specific antigen (PSA). (92nd Annual Meeting of the American Urological Association) J Urol 157(4):331.
Liang, T. and S. Liao. 1992. Inhibition of steroid 5(-reductase by specific aliphatic unsaturated fatty acids. Biochem J 285(Pt. 2):557562.
Mandressi, A. et al. 1987. Treatment of uncomplicated benign prostatic hypertrophy (BPH) by an extract of Serenoa repens. Clinical results. J Endocrinol Invest 10(suppl. 2):49.
McGuffin, M., C. Hobbs, R. Upton, A. Goldberg. 1997. American Herbal Product Association's Botanical Safety Handbook. Boca Raton: CRC Press.
Metzker, H., M. Kieser, U. Hlscher. 1996. Efficacy of a combined Sabal-Urtica preparation in the treatment of benign prostatic hyperplasia. Urologie [B] 36:292300.
Pannunzio, E. et al. 1987. Serenoa repens in the treatment of human benign prostatic hypertrophy (BPH). J Urol 137(4) Part 2:226A.
Rhodes, L. et al. 1993. Comparison of finasteride (Proscar(), a 5a reductase inhibitor, and various commercial plant extracts in in vitro and in vivo 5a reductase inhibition. Prostate 22(1):4345.
Roveda, S. and P. Colombo. 1994. Clinical controlled trial on therapeutic bioequivalence and tolerability of Serenoa repens oral capsules 160 mg or rectal capsules 640 mg. Arch Medicina Interna 46(2):6175.
Semino, M. et al. 1992. [Symptomatic treatment of benign prostatic hyperplasia (BHP): A comparative study of Prazosin and Serenoa repens] [In Spanish] Arch Esp Urol 45(3):211213.
Skeland J. and J. Albrecht. 1997. [A combination of Sabal and Urtica extracts vs. finasteride in benign prostatic hyperplasia (stage I to II acc. to Alken): A comparison of therapeutic efficacy in a one year double-blind study] [In German]. Urologe A 36(4):327333.
Sultan, C. et al. 1984. Inhibition of androgen metabolism and binding by a liposterolic extract of Serenoa repens B in human foreskin fibroblasts. J Steroid Biochem 20(1):515519.
This material was adapted from The Complete German Commission E MonographsTherapeutic Guide to Herbal Medicines. M. Blumenthal, W.R. Busse, A. Goldberg, J. Gruenwald, T. Hall, C.W. Riggins, R.S. Rister (eds.) S. Klein and R.S. Rister (trans.). 1998. Austin: American Botanical Council; Boston: Integrative Medicine Communications.
1) The Overview section is new information.
2) Description, Chemistry and Pharmacology, Uses, Contraindications, Side Effects, Interactions with Other Drugs, and Dosage sections have been drawn from the original work. Additional information has been added in some or all of these sections, as noted with references.
3) The dosage for equivalent preparations (tea infusion, fluidextract, and tincture) have been provided based on the following example:
- Unless otherwise prescribed: 2 g per day of [powdered, crushed, cut or whole] [plant part]
- Infusion: 2 g in 150 ml of water
- Fluidextract 1:1 (g/ml): 2 ml
- Tincture 1:5 (g/ml): 10 ml
4) The References and Additional Resources sections are new sections. Additional Resources are not cited in the monograph but are included for research purposes.
This monograph, published by the Commission E in 1994, was modified based on new scientific research. It contains more extensive pharmacological and therapeutic information taken directly from the Commission E.
Excerpt from Herbal Medicine: Expanded Commission E Monographs
Copyright 2000 American Botanical Council
Published by Integrative Medicine Communications
Available from the American Botanical Council.