Saw Palmetto for Hair Loss: What the Research Shows

Saw palmetto has produced measurable hair-growth improvements in human studies. A newer placebo-controlled trial adds to that evidence, while an earlier direct comparison found a larger proportion of men improved with finasteride.

A two-year comparison with finasteride

A 2012 study followed 100 men with mild to moderate androgenetic alopecia. Researchers compared 320 mg of saw palmetto daily with 1 mg of finasteride and assessed changes using photographs.

Hair growth improved in 38% of the saw-palmetto group and 68% of the finasteride group. Those percentages describe the men who improved, not the amount of new hair. Saw palmetto’s improvement was mainly at the crown; finasteride also helped the frontal area. The study was open-label, meaning treatment assignments were known.

What the newer trial adds

A 2025 randomized, double-blind trial enrolled 60 adults with self-perceived thinning hair. Forty received 160 mg/day of a proprietary saw-palmetto extract and 20 received placebo.

After 90 days, the extract group’s average terminal-hair count rose from 132.9 to 144.2 in the measured front scalp area and from 167.1 to 179.2 in the back area. Each site covered one square centimeter. These gains were statistically greater than with placebo.

That is encouraging human evidence for the tested preparation. The report covers only the first 90 days, and the extract supplier, Valensa International, sponsored the study. No treatment-related adverse events were reported during that period; it was not a safety comparison with finasteride or dutasteride.

A possible role for inflammation

In a 2018 experiment, saw-palmetto extract improved hair density and thickness in DHT-treated mice and reduced inflammatory changes. Accompanying cell experiments found improved cell survival. This is promising work on how the extract may act, but it was not a human study.

The studies used different extracts and doses. They do not establish that increasing the dose or adding other supplements improves the result. Our PalmettoGuard product listing describes a separate formulation sold by MPB Research, not the proprietary extract used in the 2025 trial.