Saw Palmetto vs Finasteride for Hair Loss
One is a plant extract sold as a supplement, the other a prescription medicine approved for male pattern hair loss. The one head-to-head study, what it found, and why the comparison is not like for like.
Saw palmetto is not a substitute for finasteride. In the one head-to-head study we found, an open-label 2012 trial of 100 men over two years, 38% of men on saw palmetto had more hair growth against 68% on finasteride. The NIH's complementary-health centre says the evidence for saw palmetto in male-pattern hair loss is too limited to allow conclusions, while finasteride is a prescription medicine the FDA has approved for male pattern hair loss in men.
This entry is information only, written from published sources on 22 September 2026 and not reviewed by a clinician. It does not give doses for either product; finasteride is prescribed, and its label and your prescriber decide how it is used.
Why people compare them
The direct answer: both are described as acting on DHT, the hormone that drives male pattern hair loss, so saw palmetto is often marketed as the "natural finasteride".
Finasteride, according to its FDA label, inhibits the type II 5-alpha-reductase enzyme that converts testosterone to DHT. Saw palmetto, a plant extract, is claimed to act on the same pathway, and it appears in several hair supplements, including Nutrafol Men, where the brand ties it to DHT support. The shared story is why people search for one against the other. The evidence behind each is very different.
The one head-to-head study
The direct answer: in a two-year, open-label study of 100 men with mild to moderate male pattern hair loss, more men improved on finasteride than on saw palmetto.
The study, by Rossi and colleagues in Rome, was published in 2012 in the International Journal of Immunopathology and Pharmacology. The men were split into a saw palmetto group and a finasteride group for 24 months, and improvement was scored by comparing photographs from the start and the end.
Share of men with more hair growth after two years
- Results: 38% of the saw palmetto group had an increase in hair growth, against 68% of the finasteride group.
- Where on the head: the authors observed that finasteride acted at both the front and the crown, while saw palmetto acted mainly at the crown.
- Limits: the study was open-label, so everyone knew what they were taking, and there was no placebo group. It shows that finasteride did better in this group of men; it cannot show how much of either result a placebo would have produced.
The authors themselves concluded that saw palmetto could lead to an improvement and that finasteride confirmed its efficacy, and they called for more studies.
What the official summaries say
The direct answer: the NIH says saw palmetto's hair-loss evidence is too limited; the FDA label says finasteride is indicated for male pattern hair loss in men only.
The National Center for Complementary and Integrative Health, part of the NIH, updated its saw palmetto fact sheet in April 2025. It says a few small studies have tested saw palmetto, taken by mouth or applied to the scalp, for male-pattern hair loss, and that the evidence is too limited to allow conclusions. It describes saw palmetto as well tolerated, with mild and infrequent side effects such as digestive symptoms, dizziness and headache, and warns that it may be unsafe during pregnancy or while breastfeeding. It also notes that saw palmetto does not appear to affect PSA readings, a prostate blood test.
Finasteride's FDA-approved label for its hair-loss brand, Propecia, says it is indicated for male pattern hair loss in men only, and it is not indicated for women. The Propecia label version on DailyMed dated 14 October 2024 lists its own side effects and warnings, including sexual side effects and post-marketing reports of depression and suicidal ideation, which a prescriber discusses before starting it. That conversation is exactly why it needs a prescription.
Why the two are not interchangeable
- Regulation: finasteride is an approved medicine; saw palmetto is a dietary supplement that the FDA does not approve before sale. See how hair supplements are (not) regulated in the US.
- Evidence: finasteride's approval rests on its own clinical trial programme; saw palmetto's hair evidence is, in NIH's words, too limited for conclusions.
- Consistency: supplement extracts can vary between brands; a prescription medicine is made to a fixed standard.
- Supervision: a prescriber can weigh finasteride's side effects against your history. Nobody does that for an over-the-counter capsule unless you ask.
Saw palmetto inside blends
The direct answer: most people meet saw palmetto inside a multi-ingredient hair supplement, where its own effect cannot be separated from everything else.
Nutrafol Men lists saw palmetto as one of six headline ingredients, alongside curcumin, ashwagandha, tocotrienols, marine collagen and hyaluronic acid, plus vitamins and minerals. A trial of the whole capsule can show whether the capsule beat placebo; it cannot show whether saw palmetto did anything. A 2025 case report also lists saw palmetto among the ingredients in one Nutrafol label that carry a liver-injury likelihood grade in the US Drug-Induced Liver Injury Network scheme, although it sits in a lower-likelihood category than turmeric. Our entry on Nutrafol ingredients, one by one covers the rest of the list.
Saw palmetto shampoos and scalp products
The direct answer: applying saw palmetto to the scalp falls under the same verdict. The NIH fact sheet covers saw palmetto used by mouth or applied to the scalp, and calls the evidence for either route in male-pattern hair loss too limited to allow conclusions. A shampoo that rinses off quickly has even less time to act than a leave-on product, so treat saw palmetto shampoo claims with the same caution as the capsules.
Women and saw palmetto
The direct answer: this comparison is about men. Finasteride's label says it is not indicated for women, and the NIH says saw palmetto may be unsafe during pregnancy or breastfeeding, so women considering either should speak to a doctor first.
If you are weighing a supplement against a prescription
The direct answer: talk to a GP or dermatologist about both before choosing either, and do not stop or swap a prescribed medicine on the strength of a supplement's marketing.
A consultation pays this site nothing. If a doctor is comfortable with you trying a supplement that contains saw palmetto, our Nutrafol review explains what its one men's trial did and did not measure, and Nutrafol for men covers where it might fit. On our supplement evidence grades, saw palmetto on its own is graded "Weak".