Saw Palmetto

Also indexed as:Sabal, Sabal serrulata, Serenoa repens, Serenoa serrulata
Saw Palmetto: Main Image© Steven Foster
Common names:
Sabal
Botanical names:
Sabal serrulata, Serenoa repens, Serenoa serrulata

How It Works

The liposterolic (fat-soluble) extract of saw palmetto provides concentrated amounts of free fatty acids and sterols. One study with a saw palmetto extract suggests that it reduces the amount of dihydrotestosterone (DHT) (an active form of testosterone) binding in the part of the prostate surrounding the urethra (the tube carrying urine from the bladder).12 Test tube studies also suggest that saw palmetto weakly inhibits the action of 5-alpha-reductase, the enzyme responsible for converting testosterone to DHT.13 In test tubes, saw palmetto also inhibits the actions of growth factors and inflammatory substances that may contribute to benign prostatic hyperplasia (BPH). Contrary to some opinions, saw palmetto does not have an estrogen-like effect in men’s bodies.

Over the last decade, double-blind clinical trials have proven that 320 mg per day of the liposterolic extract of saw palmetto berries is a safe and effective treatment for the symptoms of BPH. A recent review of studies, published in the Journal of the American Medical Association, concluded that saw palmetto extract was as effective as finasteride (Proscar®) in the treatment of BPH.14 The clinical effectiveness of saw palmetto has been shown in trials lasting six months to three years.

A three-year trial in Germany found that taking 160 mg of saw palmetto extract twice daily reduced nighttime urination in 73% of patients and improved urinary flow rates significantly.15 In a double-blind trial, 160 mg of saw palmetto extract taken twice daily was found to treat BPH as effectively as finasteride (Proscar) without side effects, such as loss of libido.16

Saw palmetto extract has also been combined with a nettle root extract to successfully treat BPH. One trial using a combination of saw palmetto extract (320 mg per day) and nettle root extract (240 mg per day) showed positive actions on symptoms of BPH (e.g. improved urine flow, decreased nighttime urination, etc.) over a one-year treatment period.17 Another study compared the same combination to finasteride for one year with positive results.18

How to Use It

For early-stage BPH, 160 mg per day of liposterolic saw palmetto herbal extract in capsules is taken two times per day. One trial suggested that 320 mg once per day may be equally effective.19 It may take four to six weeks to see results with BPH. If improvement is noted, the saw palmetto should be used continuously. It is important to work closely with a urologist to determine clinical improvement. Although it has not been tested for efficacy, saw palmetto is occasionally taken as a tea made with 5–6 grams of the powdered dried fruit. Ground, nonstandardized berry preparations (1–2 grams per day) and liquid extracts of whole herb at 5–6 ml per day are also sometimes used but have not been specifically tested.

Copyright © 2014 Aisle7. All rights reserved. Aisle7.com

Learn more about Aisle7, the company.

Learn more about the authors of Aisle7 products.

The information presented in Aisle7 is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires June 2015.

Navigation