Saw Palmetto for Thinning Hair in Women: What the Studies Show

Saw palmetto, an extract from the berries of a small palm, is a common ingredient in hair supplements, gummies and scalp serums marketed to women with thinning hair. It’s thought to have anti-androgen effects, which is why it’s linked with pattern hair loss. Here is what the research shows.

What the reviews say

• NCCIH: The National Center for Complementary and Integrative Health¹ says a few small studies have tested saw palmetto, by mouth or on the scalp, for male-pattern hair loss, and the evidence is too limited to draw conclusions.¹
• A 2020 systematic review found five randomized trials and two smaller studies of supplements containing saw palmetto for pattern hair loss and shedding. Results were positive, but the authors said high-quality data are lacking. Many products combined saw palmetto with other ingredients, so its own contribution is unclear.²

A closer look at one trial

In a 2023 trial³, 80 men and women aged 18 to 50 with mild-to-moderate pattern hair loss took a standardized saw palmetto oil capsule, used a topical version, or used a placebo for 16 weeks. Hair density rose about 5% with the capsule and about 8% with the topical form. There was no significant change in the ratio of growing to resting hairs.³

That trial tested one company’s extract in a younger group. Results may not apply to other products or to women after menopause.

Safety

NCCIH says saw palmetto is generally well tolerated and has been used safely in studies for up to 3 years. Side effects are uncommon and mild, such as digestive upset, dizziness and headache. It may be unsafe during pregnancy or breastfeeding.¹ Talk with your clinician before taking any herb if you take other medicines.¹

Supplements aren’t approved by the FDA before they’re sold, so the amount and quality of saw palmetto vary between products.¹

Where it fits

For female pattern hair loss, the American Academy of Dermatology⁴ calls minoxidil the most-recommended treatment.⁴ Our guide to topical minoxidil explains the options. Thinning after 50 can also come from thyroid problems, low iron or other causes worth testing. See our article on why hair thins.

If you try a saw palmetto product:

1. Check the label for the amount of saw palmetto and other ingredients.
2. Take dated photos of your part in the same light before you start and every month.
3. Give it about four months, the length of the 2023 trial³, before deciding.³
4. Don’t stop a proven treatment to try it without talking to your dermatologist.

Try: “I’m thinking about a saw palmetto supplement for my thinning part. Is it safe with my other medicines, and would it add anything to minoxidil?”

Hair, Everywhere includes a Hair Check and a monthly Hair Log. Use them to record what you take and track dated photos, so you can see whether anything is working. See the book.