Saw Palmetto Oily Fruit Extract

Oily saw palmetto fruit extract is a plant extract obtained from the fruit of saw palmetto, Serenoa repens: compounds are dissolved out of the fruit with a solvent, hexane or ethanol, which is then partly evaporated, leaving a soft extract. Medicines made with it are used for urinary symptoms of an enlarged prostate in adult men.

Use in medicines

The two kinds of extract rest on different evidence. The extract made with hexane is used for the symptoms of benign prostatic hyperplasia, a non-cancerous enlargement of the prostate, on the basis of scientific publications covering at least 10 years. Extracts made with ethanol are traditionally used, on the basis of long experience rather than clinical trials, for urinary symptoms such as difficulty starting urination or a frequent need to urinate, after a doctor has ruled out serious conditions. Both are for adult men only.

Health Canada's monograph lists the fat-soluble (liposterolic) extract, standardised to 70–95% fatty acids, at 100–400 mg a day for the same symptoms in adult men, who should first see a doctor to rule out prostate cancer. A 2023 review of 27 studies found that saw palmetto alone gives little or no benefit for these symptoms, and found no difference between hexane extracts and other products. How the extract works is not fully known; laboratory studies suggest that it reduces the action of male sex hormones such as testosterone and may have anti-inflammatory effects.

Safety

Common side effects of saw palmetto fruit medicines, in 1 to 10 people in 100, are belly pain and headache.

Products containing it

• Sabal Forte capsules (D 235)