Saw palmetto

Also known as serenoa repens, saw palmeto.

Last reviewed October 9, 2026 · Jump to references

What is Saw palmetto?

In plain words

Saw palmetto is an extract made from the berries of a small palm tree. The body breaks down and processes its mixture of fats and plant compounds, which may affect hormone-related pathways. Researchers study it for urinary symptoms linked to an enlarged prostate and for hair loss. High-quality studies have generally found little or no benefit for prostate-related urinary symptoms compared with a dummy treatment.

Technical definition

Saw palmetto (Serenoa repens) is a botanical derived from the fruit of a small palm native to the southeastern United States; its extracts contain fatty acids and phytosterols. Laboratory studies suggest inhibition of 5-alpha-reductase, the enzyme that converts testosterone to dihydrotestosterone (DHT), but a clinically meaningful effect on this pathway is not established. In the United States, it is marketed as a dietary supplement and is not FDA-approved to treat disease.

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Evidence by use

Each use is rated on its own. There is no single overall effectiveness score.