Serenoa repens. A small fan palm native to the southeastern United States. Its berries are used in supplements for prostate symptoms and hair loss.
What the research supports
The STEP trial (225 men, one year), the CAMUS trial (369 men, up to triple dose) and Cochrane reviews covering more than 5,000 men all found that saw palmetto did not improve urinary symptoms from an enlarged prostate more than placebo. Evidence for hair loss is small and low quality.
The dose that was actually studied
320 mg a day of fat-soluble berry extract, and up to 960 mg in the CAMUS trial.
What to look for on a label
- Berry extract labeled Serenoa repens
- A clearly stated amount per serving
Who should not take it
- Women who are pregnant or might become pregnant
- Anyone using it in place of a medical check-up for urinary symptoms
Read the full guide: Saw Palmetto for the Prostate: What the Big Trials Found.
This profile is for general education and is not medical advice. Talk to your doctor or pharmacist before starting a supplement, especially if you take medication or have a health condition.




