Saw palmetto for hair loss: what it does, how it compares to finasteride

What saw palmetto is

Saw palmetto (Serenoa repens) is a small palm from the southeastern United States. Extracts of its berries have long been sold for prostate symptoms^[3]. In the Philippines it shows up in men's prostate supplements, hair gummies and PCOS stacks, sold on Shopee, Lazada and iHerb.

The hair loss theory is simple. Pattern hair loss is driven by DHT, made from testosterone by the enzyme 5-alpha reductase. Finasteride blocks that enzyme strongly. Saw palmetto is thought to block it weakly. That is why it gets called natural finasteride, a label that overstates the evidence.

What the evidence says

The best-known study compared saw palmetto with finasteride 1mg in men with pattern hair loss over two years. Hair growth improved in 38% of men on saw palmetto, against 68% of men on finasteride^[1]. Saw palmetto did something, but clearly less. The study was not blinded, which weakens it.

A small earlier placebo-controlled trial of a saw palmetto and beta-sitosterol supplement reported improvement in some men^[4], but it was tiny. A 2020 systematic review concluded that saw palmetto may offer some benefit, but the studies are few, small and varied in product and dose, and it should not replace proven treatments^[2].

Saw palmetto for women and PCOS

Women with PCOS often have higher androgen levels, which can cause thinning at the part and crown along with acne and excess facial hair. Saw palmetto is popular in this group as a gentler-sounding anti-androgen.

There are no good trials of saw palmetto for PCOS hair loss specifically. Because it may act on hormones, it is not recommended during pregnancy or while trying to conceive without a doctor's advice^[3]. If you have PCOS symptoms, a dermatologist or OB-GYN can discuss options with stronger evidence. See PCOS hair loss and the female hair loss guide.

Reading the label in the PH

Saw palmetto products vary more than most supplements. Some contain a standardised extract of the berry's oils. Others contain ground whole berry powder, which is a different thing. Many hair products bury a small amount of saw palmetto in a long list of vitamins and herbs. The two-year trial used a specific extract^[1], and you cannot assume a random gummy matches it.

• Look for the extract type and amount per capsule, not just the words saw palmetto.
• Prefer single-ingredient products if you want to know whether it is working.
• Check the FDA registration number on the box. Imported iHerb products ship to you as a personal order, so registration may not apply in the same way; buy from established sellers.
• Note that prostate formulas are marketed to older men for urinary symptoms^[3]. They are the same plant, but the product is designed for a different use.

Side effects and safety

Saw palmetto is generally well tolerated in studies. The most common complaints are mild stomach upset and headache^[3]. It has not been linked to the sexual side effects that worry men about finasteride in the same way, though the data are much thinner, so absence of reports is not proof of safety.

• Tell your doctor about any supplement, especially if you take other medicines or hormone therapy.
• Check the product on the FDA verification portal^[8]. The PH FDA has warned about unregistered hair products sold online^[9].
• Be wary of supplements that combine saw palmetto with undisclosed drugs, or that promise regrowth.

For the full picture of risks across hair loss treatments, see the side effects hub, and for finasteride's real side effect rates, see finasteride side effects.

Is it worth it?

If you have clear pattern hair loss and are open to prescription treatment, finasteride does more, and branded 1mg costs ₱1,800 a month. Topical minoxidil at about ₱600 to ₱900 a month works by a different route and can be combined. See minoxidil vs finasteride.

If you want to avoid finasteride entirely, saw palmetto is a reasonable thing to try alongside minoxidil, with honest expectations. Another middle option is topical finasteride, which reduces whole-body exposure compared with tablets^[10]. Whatever you choose, take monthly photos in the same light and reassess with a doctor after a fixed period, rather than switching products every few weeks. Hair grows slowly, and any treatment, natural or prescription, needs months before you can judge it. If you notice faster thinning while on saw palmetto alone, that is a sign to move up the ladder, not to add another supplement.

Not sure what kind of hair loss you have? A PDS board-certified dermatologist consult costs ₱400 to ₱1,000, or compare online hair loss doctors. The full hair loss treatment ladder and prices page show where saw palmetto fits. Related: biotin for hair and rosemary oil for hair.