Saw Palmetto

Saw palmetto is an extract derived from the berries of the Serenoa repens plant and is sold as an oral supplement or topical formulation. It is thought to affect hair by supplying fatty acids and phytosterols that may inhibit the enzyme 5-alpha-reductase, which converts testosterone into dihydrotestosterone (DHT), a hormone associated with androgenetic hair loss.

Evidence for saw palmetto’s effectiveness in treating hair loss is limited and mixed, with some small studies suggesting modest benefit but larger, high-quality trials lacking, and it is not approved by regulatory authorities for hair regrowth. Potential side effects include gastrointestinal upset, headache, and interactions with anticoagulants or hormonal medications, and it should be used only after consulting a healthcare professional, especially during pregnancy or breastfeeding.