Saw Palmetto Benefits: Does It Work, Side Effects and Dose

What to buy

Two softgels give the 320 mg of extract the big trials used, at the lowest cost per day of the products that pass our label checks.

Where to go next

• Best saw palmetto: our pick, a bottle on a testing list, and every product we checked.
• Saw palmetto dosage guide: how much by form, once or twice a day, and how to take it.

What saw palmetto does

Saw palmetto comes from the berries of a small palm that grows in the southeastern US. Supplements use an oil extract of the berry. In lab studies the extract blocks 5-alpha-reductase, the enzyme that turns testosterone into DHT (Plosker 1996). Here is what studies in people found.

Does saw palmetto work for urinary symptoms?

Not in the largest trials. In STEP, 225 men over 49 took 160 mg twice a day or a placebo for a year; symptom scores, urine flow and prostate size did not differ (Bent 2006). In CAMUS, 369 men took up to 960 mg a day for 72 weeks, and the placebo group did slightly better (Barry 2011). A 2023 Cochrane review of 27 studies and 4,656 men found little to no benefit (Franco 2023).

One extract has some better results. Reviews of Permixon, made with hexane and sold in Europe, found fewer night-time trips and a stronger urine flow than placebo (Novara 2016; Vela-Navarrete 2018). European urology guidelines (2021) say doctors may offer it to men who want to avoid the sexual side effects of drugs, and should tell them the benefit may be modest. A 2021 review of 22 trials by a group of European urologists found no meaningful benefit from saw palmetto overall (Russo 2021). No product we checked says it is made with hexane, so those results may not carry over to them.

Urinary symptoms can come from other causes, so see a doctor before you treat them yourself.

Does saw palmetto help thinning hair?

The research is small. In a pilot trial, 6 of 10 men on saw palmetto with beta-sitosterol were rated improved (Prager 2002). In a 2-year study of 100 men without a placebo group, 38% on 320 mg a day had more hair against 68% on finasteride (Rossi 2012). NCCIH says the evidence is too limited to draw conclusions.

Saw palmetto for women

One branded extract was tested against a placebo in 60 adults with thinning hair, and half were women; menopausal women had more hair after 180 days than those on placebo, but the groups were small (Ablon 2025, 2026). We found no human trials of saw palmetto for PCOS or unwanted facial hair. No dose has been set for women, and it is not for pregnancy (who should skip it).

How much to take

Take 320 mg of standardized extract a day, once or split in two. The dosage guide covers berry powder, higher doses and how to take it.

Is saw palmetto safe?

For most adults, yes. NCCIH says it is well tolerated and has been used safely in studies for up to 3 years. Side effects are mild and infrequent: stomach upset, dizziness and headache.

Who should ask a doctor first?

Skip it if you are pregnant or breastfeeding; NCCIH says it may be unsafe then. Ask first if you take any prescription medicine, and tell your surgeon before an operation: one case report linked saw palmetto to heavy bleeding during surgery (Cheema 2001).

Read the label, not the front of the bottle

Many bottles hold ground berry or a blend, not the extract the trials used. We read 17 labels of top saw palmetto supplements, and only 9 pass all three of our label checks.

Questions people ask