Research review
What does saw palmetto do for women?
Almost all saw palmetto research has studied men. The exception is a recent placebo-controlled trial that included women (half the participants) and found a hair-growth benefit in the menopausal subgroup specifically. Outside of that one trial, there's no dedicated safety or effectiveness research on saw palmetto in women, for any use.
The evidence doesn't support most of what saw palmetto is marketed for in women, simply because almost none of the research included women at all. The large prostate and urinary-symptom trials studied men exclusively. The one exception is a recent placebo-controlled trial that included women and found a hair-growth benefit in the menopausal subgroup — a real, if narrow, update to a research base that has otherwise been about men.
What the evidence doesn't support
It doesn't support saw palmetto as a treatment for PCOS, hormonal acne, menstrual symptoms, or menopause symptoms in women — no human trial has tested it for any of those. It doesn't support the idea that the safety data described elsewhere on this site (from trials of men) simply carries over to women; no dedicated safety trial in women exists. And outside the hair trial below, it doesn't support any specific benefit for women that hasn't also been tested, and found negative, in men — the large negative urinary-symptom trials were men-only, so there isn't even a female comparison point for that use.
What the trials found
A 2025-2026 randomized, double-blind, placebo-controlled trial tested a specific saw palmetto extract (160 mg/day) in 60 adults with self-perceived thinning hair, and — unusually for saw palmetto research — half the participants were women. At the 90-day mark, the treated group as a whole showed significantly more hair than placebo. By 180 days, the trial's own subgroup analysis found a significant, placebo-adjusted benefit specifically in menopausal women: more terminal hair and greater hair density than the placebo group, with no treatment-related adverse events reported. That's a genuine, dedicated finding in women, from one well-designed trial — not yet independently repeated, and specific to one extract and dose, not saw palmetto generally.
On the hormonal side, a 2026 rat study modeled PCOS in female rats using the drug letrozole, then gave separate groups of those rats saw palmetto fruit extract at 160 or 320 mg/kg body weight. Compared with an untreated group of PCOS-model rats, the saw palmetto groups showed improved hormone and lipid levels and more normal ovarian tissue. That's a legitimate animal finding worth following up — and it's a rat study, not a test in a woman, with a dose that doesn't translate to a human capsule size. No human PCOS trial of saw palmetto exists.
A separate, older laboratory study found that one specific saw palmetto extract blocks an enzyme involved in converting testosterone into DHT, in cells in a dish. That's sometimes cited as a reason saw palmetto might affect androgen-related symptoms like acne or hirsutism in women, but no trial has measured whether it actually changes hormone levels, skin, or hair growth in a woman taking a capsule.
Questions people ask
What does saw palmetto do for women?
Based on the evidence available, not much has been directly tested. The one dedicated finding is a placebo-controlled trial showing a hair-growth benefit in menopausal women at 180 days, using a specific 160 mg/day extract. Beyond that, most of what saw palmetto is marketed for in women — PCOS, acne, hormone balance — has no human research behind it.
Is saw palmetto safe for women?
No dedicated safety trial in women exists. The hair trial above, which included women, reported no adverse events over 180 days, but that's one trial testing one outcome, not a comprehensive safety study. See is it safe to take saw palmetto every day for the broader safety picture, most of which comes from men.
Does saw palmetto increase estrogen in women?
No trial has measured estrogen levels in women taking saw palmetto. A small blend study in men found an estrogen (estradiol) decrease at the higher dose tested, but that tested saw palmetto combined with another ingredient in men, not saw palmetto alone in women — see does saw palmetto raise or lower testosterone for that study's detail.
Can women take saw palmetto for PCOS?
No human trial has tested that. A rat study found improved hormone and ovarian markers in a PCOS animal model given saw palmetto extract, compared with an untreated PCOS-model group — an early animal signal, not evidence for a woman with PCOS. Full detail is in does saw palmetto help with PCOS or diabetes?
When to talk to a doctor
Saw palmetto is not a treatment for PCOS, hormonal acne, or any diagnosed menstrual or menopause-related condition in women. If you're pregnant or nursing, saw palmetto hasn't been studied in that population and should be avoided or discussed with a doctor first — see who should not take saw palmetto. Irregular periods, unusual hair growth or loss, or persistent acne are worth a doctor's evaluation regardless of any supplement.
Related reading: does saw palmetto help hair growth?, does saw palmetto help with PCOS or diabetes?, and does saw palmetto help with acne or oily skin?
Sources
- The Safety and Efficacy of a Proprietary Bioactive Fatty Acids Extract From Saw Palmetto (Serenoa repens) for Promoting Hair Growth and Reducing Hair Loss in Adults With Self-Perceived Thinning Hair: 90-Day Results A placebo-controlled trial of a specific 160 mg/day saw palmetto extract found significantly greater hair counts than placebo at 90 days in 60 adults, half of them women.
- The Safety and Efficacy of a Novel Saw Palmetto (Serenoa repens) Extract for Promoting Hair Growth in Adults With Self-Perceived Thinning Hair: 180-Day Results The 180-day results of the same trial found the treated group's advantage over placebo grew larger between Day 90 and Day 180, in both men and menopausal women.
- Serenoa repens (saw palmetto): a systematic review of adverse events A systematic review of 40 studies found saw palmetto's side effects are usually mild and similar in frequency to placebo — mainly stomach upset, headache, fatigue and decreased libido — with serious events reported only in isolated case reports of uncertain cause.
- Novel therapeutic potential of Serenoa repens in rat PCOS: Insights from network pharmacology and in vivo studies A 2026 rat study found saw palmetto extract improved hormone and lipid markers and reduced ovarian tissue abnormalities compared with an untreated PCOS rat model, at 160 and 320 mg/kg body weight — a rat finding, not evidence of an effect in a person.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.