Saw Palmetto

Saw Palmetto
Botanical Name:  Serenoa repens/Sabal serrulata
Plant Description
What's It Made Of?
Available Forms
How to Take It
Possible Interactions
Supporting Research


The berries of the saw palmetto (Serenoa repens/Sabal serrulata), a fan palm native to the southeastern United States, act to increase urine flow, to diminish inflammation, and to reduce muscle spasms. In Europe, saw palmetto is widely used to treat benign prostatic hyperplasia, or BPH, which is an enlargement of the prostate gland (see details below). In the United States, it ranks among the top ten dietary supplements in terms of sales.

Saw palmetto berries were a staple food among native Americans of the southeastern United States, who also used them to treat digestive problems, genitourinary inflammation, dysentary, and lack of libido. Early in the 20th century, saw palmetto was listed in the US Pharmacopoeia as an effective remedy for enlargement of the prostate gland (called benign prostatic hyperplasia or BPH), urinary tract inflammation, cystitis (bladder inflammation), breast disorders, bronchitis, and laryngitis.

Benign Prostatic Hyperplasia (BPH)
In BPH, cells in the prostate gland (a tiny gland that lies behind the urethra) grow too quickly. The gland swells and presses on the urethra, creating the constant sensation of a need to urinate. The majority of men over 60 have urinary symptoms attributable to BPH, which can disturb sleep, affect self-confidence, cause constant low-grade anxiety or even pain, and may progress to infections in the bladder or kidneys.

Saw palmetto is comparable to finasteride (a common prescription drug that slows or stops the progression of BPH) in relieving symptoms of BPH during its early stages. Such symptoms include frequent need to urinate, a delay before being able to urinate, dripping after urinating, and having to get up numerous times throughout the night to urinate. While saw palmetto appears to produce symptom relief in a much shorter time than finasteride, one important difference between the two is that finasteride shrinks the size of the prostate, and saw palmetto only relieves the symptoms of BPH without changing the size of the prostate. Also, studies to date of saw palmetto have not evaluated the safety of the herb for long periods of time.

Prostate Cancer
Saw palmetto is also one of the eight herbal ingredients that make up PC-SPES, a Chinese herbal treatment for prostate cancer that is gaining popularity in the West as a possible alternative to conventional therapy for this condition. Research on PC-SPES is ongoing and may prove to be of particular interest for men who do not respond to surgery, radiation, or medication. (It is important to note, however, that the U.S. Food and Drug Administration [FDA] recently issued a warning to consumers that PC SPES may contain undeclared prescription drug ingredients that could cause dangerous side effects.)

Because it effects both male and female sex hormones, saw palmetto may also be useful in treating such conditions as hirsutism (excessive growth of dark, coarse body and facial hair in women) and polycystic ovarian disease (multiple cysts in the ovaries that leads to irregular or absent menses and, possibly, infertility) in women.

Plant Description

Saw palmetto is a fan palm that can reach heights of 10 feet in warm climates. In the United States, it grows in the warm climates of the southeast, from South Carolina to Mississippi and throughout Florida. Lush, green leaves fan out from thorny stems. The plant bears white flowers, which develop yellow olive-like berries. The berries, when ripe, turn bluish-black and are dried for medicinal use.

What's It Made Of?

Saw palmetto's active ingredients include fatty acids, plant sterols, and flavonoids. However, most likely these are not the only substances within the berries that affect hormone production, and it will take more scientific study to determine exactly how saw palmetto works.

The berries also contain high-molecular-weight polysaccharides, which are usually associated with either anti-inflammatory or immune-stimulant effects.

Available Forms

Saw palmetto can be purchased as dried berries, tea, powdered capsules, tablets, liquid tinctures, and liposterolic extracts. The product label should indicate that contents are standardized and contain 85% to 95% fatty acids and sterols. In a evaluation, approximately 63% of the leading brands of saw palmetto were standardized to this amount appropriately; this means that as many as 37% were not. Again, read labels carefully to make sure that they are labeled as containing 85% to 95% fatty acids and sterols and buy from reputable companies.

How to Take It


There are no known scientific reports on the pediatric use of saw palmetto. Therefore, it is not currently recommended for children.


The recommended dosages for early stages of BPH is 160 mg, two times per day, of a fat-soluble saw palmetto extract, which has been standardized to contain 85% to 95% fatty acids and sterols.


Because of the potential for side effects and interactions with medications, herbs should be taken only under the supervision of a knowledgeable healthcare provider. That said, saw palmetto is a very mild herb and The American Herbal Products Association gives saw palmetto a class 1 safety rating, which means that it is safe when used as directed. Side effects are very rare, although mild stomach complaints and minor headaches may occur; also, one case of significant bleeding during surgery, attributed to saw palmetto use prior to the operation, has been reported.

It is important that those with BPH be under the supervision of a healthcare provider who can determine the best treatment and monitor its effects.

Saw palmetto has not been studied or used in women who are pregnant or nursing; therefore, it should not be used during pregnancy or while breast-feeding. In addition, saw palmetto may, in theory, interfere with the absorption of iron -- another reason not to use this herb if pregnant or nursing, since iron is necessary for the mother, fetus, and baby.

Possible Interactions

There are no reports in the scientific literature to suggest that saw palmetto interacts with any conventional medications. However, because saw palmetto may work similarly to finasteride, it has been recommended that this herb not be used in combination with finasteride or other medications used to treat BPH.

Supporting Research

Blumenthal M, Goldberg A, Brinckmann J. Herbal Medicine: Expanded Commission E Monographs. Newton, MA: Integrative Medicine Communications; 2000:335-340.

Bone K, Mill S, eds. Principles and Practices of Phytotherapy, Modern Herbal Medicine. London: Churchill Livingstone; 2000:523-532.

Braeckman J. The extract of Serenoa repens in the treatment of benign prostatic hyperplasia: A multicenter open study. Curr Therapeut Res. 1994;55:776-785.

Darzynkiewicz Z, Traganos F, Wu JM, Chen S. Chinese herbal mixture PC-SPES in treatment of prostate cancer (Review). Int J Oncol. 2000;17:729-736.

De La Taille A, Buttyan R, Hayek O, et al. Herbal therapy PC-SPES: In vitro effects and evaluation of its efficacy in 69 patients with prostate cancer. J Urol. 2000;164:1229-1234.

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 Uro.1992;21:309-314.

el-Sheikh M, Dakkak MR, Saddique A. The effect of permixon on androgen receptors. Acta Obstet Gynecol Scand. 1988;67:397-399.

Ernst E. Herbal medications for common ailments in the elderly. Drugs Aging. 1999;15(6):423-428.

Ernst E. The risk-benefit profile of commonly used herbal therapies: Ginkgo, St. John's Wort, Ginseng, Echinacea, Saw Palmetto, and Kava. Ann Intern Med. 2002;136(1):42-53.

Gerber GS. Saw palmetto for the treatment of men with lower urinary tract symptoms. J Urol. 2000;163(5):1408-1412.

Gerber GS, Kuznetsov D, Johnson BC, Burstein JD. Randomized, double-blind, placebo-controlled trial of saw palmetto in men with lower urinary tract symptoms. Urology. 2001;58(6):960-965.

Izzo AA, Ernst E. Interactions between herbal medicines and prescribed drugs: a systematic review. Drugs. 2001;61(15):2163-2175.

Goepel M, Hecker U, Krege S. Saw palmetto extracts potently and noncompetitively inhibit human a1-adrenoceptors in vitro. Prostate. 1998;38(3):208-215.

Koch E. Extracts from fruits of saw palmetto (Sabal serrulata) and roots of stinging nettle (Urtica dioica): viable alternatives in the medical treatment of benign prostatic hyperplasia and associated lower urinary tracts symptoms. Planta Med. 2001;67(6):489-500.

Marks LS, Partin AW, Epstein JI, et al. Effects of saw palmetto herbal blend in men with symptomatic benign prostatic hyperplasia. J Urol. 2000;163(5):1451-1456.

Miller LG. Herbal medicinals: selected clinical considerations focusing on known or potential drug-herb interactions. Arch Intern Med. 1998;158(20):2200-2211.

O'Hara M, Kiefer D, Farrell K, Kemper K. A review of 12 commonly used medicinal herbs. Arch Fam Med. 1998;7(6):523-536.

Pittler MH. Complementary therapies for treating benign prostatic hyperplasia. FACT. 2000;5(4):255-257.

Pizzorno JE, Murray MT. Textbook of Natural Medicine. New York, NY: Churchill Livingstone; 1999:943-946,1147-1152.

Quality of prostate supplements get mixed review in study. January 31, 2000; Accessed on April 29, 2002 at

Robbers JE, Tyler VE. Herbs of Choice: The Therapeutic Use of Phytomedicinals. New York: NY: The Haworth Herbal Press; 1999:103-105.

Rotblatt M, Ziment I. Evidence-Based Herbal Medicine. Philadelphia, Penn: Hanley & Belfus, Inc.; 2002:327-331.

Small EJ, Frohlich MW, Bok R, et al. A prospective trial of the herbal supplement PC-SPES in patients with progressive prostate cancer. J Clin Oncol. 2000;18(21):3595-3603.

Sultan C, Terraza A, Devillier C, et al. Inhibition of androgen metabolism and binding by a liposterolic extract of "Serenoa repens B" in human foreskin fibroblasts. J Steroid Biochem. 1984;20(1):515-519.

Wilt TJ, Ishani A, Rutks I, MacDonald R. Phytotherapy for benign prostatic hyperplasia.
Public Health Nutr. 2000;3(4A):459-472.

Wilt TJ, Ishani A, Stark G, MacDonald R, Lau J, Mulrow C. Saw palmetto extracts for treatment of benign prostatic hyperplasia: a systemic review. JAMA. 1998;280(18):1604-1609.

Review Date: April 2002
Reviewed By: Participants in the review process include: Robert A. Anderson, MD (April 1999), President, American Board of Holistic Medicine, East Wenatchee, WA; Jacqueline A. Hart, MD, Department of Internal Medicine, Newton-Wellesley Hospital, Harvard University and Senior Medical Editor Integrative Medicine, Boston, MA; Gary Kracoff, RPh (Pediatric Dosing section February 2001), Johnson Drugs, Natick, MA; Steven Ottariono, RPh (Pediatric Dosing section February 2001), Veteran's Administrative Hospital, Londonderry, NH; R. Lynn Shumake, PD, Director, Alternative Medicine Apothecary, Blue Mountain Apothecary & Healing Arts, University of Maryland Medical Center, Glenwood, MD; David Winston, Herbalist (April 1999), Herbalist and Alchemist, Inc., Washington, NJ; Tom Wolfe, P.AHG (April 1999), Smile Herb Shop, College Park, MD. All interaction sections have also been reviewed by a team of experts including Joseph Lamb, MD (July 2000), The Integrative Medicine Works, Alexandria, VA;Enrico Liva, ND, RPh (August 2000), Vital Nutrients, Middletown, CT; Brian T Sanderoff, PD, BS in Pharmacy (March 2000), Clinical Assistant Professor, University of Maryland School of Pharmacy; President, Your Prescription for Health, Owings Mills, MD; Ira Zunin, MD, MPH, MBA (July 2000), President and Chairman, Hawaii State Consortium for Integrative Medicine, Honolulu, HI.

Copyright © 2004 A.D.A.M., Inc

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