Everything To Know About Saw Palmetto For Hair Loss

February 5, 2023 Dr. Steven Shapiro

A shrub-like plant that grows naturally in southern U.S. states and Central America, the saw palmetto (Serenoa repens) gets its name from its sharp spines surrounding palm-like leaves. Saw palmettos are popular garden plants in southern coastal states that produce long, showy leaves, yellow flowers, and grape-like fruits.

Extracts of these saw palmetto berries have become a go-to as a natural ingredient to fight hair loss triggers in men and women, both topically and orally.

Does saw palmetto work for hair loss?

Taken orally, saw palmetto supplements have not been FDA-approved for medical conditions. However, supplements with saw palmetto extracts are common on health food store shelves for a few reasons. Ongoing research indicates that Serenoa repens likely provides some benefits for the following:

Prostate enlargement (benign prostatic hyperplasia)
Improving urinary flow by reducing water retention
Mild thyroid disorders
Polycystic ovarian syndrome
Chest congestion (expectorant)
Stimulating appetite
Headaches/migraines

Saw palmetto fruits are rich in phytosterols and fatty acids that are responsible for most of this plant's medicinal properties. Clinical trials involving subjects taking hexanic extract (a saturated fatty acid vital to human and plant metabolism) have provided results showing saw palmetto may offer anti-inflammatory and anti-androgenic properties, to begin.

It’s this anti-androgenic capability that gives saw palmetto its allure in hair loss. For the same reason, saw palmetto is also one of several popular herbs possibly providing therapeutic effects for prostate enlargement and early-onset prostate cancer.

Saw palmetto berries contain phytosterols and flavonoids conducive to prostate cancer inhibition as well as fatty acids beneficial to overall health. It also may treat urinary tract issues resulting from enlarged prostates and recurring infections as well as asthma and bronchitis.

It’s worth noting the lack of peer-reviewed studies investigating benefits or side effects of eating raw saw palmetto fruit; however, Native Americans continue to eat raw saw palmetto berries for their diuretic, anti-congestion, and general nutritional properties.

What drives saw palmetto’s use in hair loss and other medical conditions? Let’s explore.

What is Androgenic Alopecia?

Androgenic alopecia (male and female pattern baldness) is estimated by the National Library of Medicine to affect over 50 million men and nearly 30 million women in the U.S. Some men may begin to experience signs of androgenic alopecia in their 20s if there is a history of male pattern baldness in their families. Women tend to notice significant hair loss after menopause due to low estrogen and higher testosterone levels.

Studies suggest variations in genes play a critical role in the development of androgenic alopecia, and these genes trigger a susceptibility to androgenic hormones (sex hormones). The AR gene, for instance, "instructs" other genes in the production of androgen receptors, specific sites on cells that respond accordingly to hormones like testosterone and dihydrotestosterone (DHT).

Researchers think that the hair follicles of men and women with the AR gene see increased inhibitory activity from sex hormones like testosterone and dihydrotestosterone that interferes with the normal progression of hair growth. This is why medications that reduce these androgens in one way or another are effective in treating hair loss.

Researchers have concluded that the mechanism of action by which saw palmetto may increase hair growth is similar to how finasteride (the only oral medication approved by the FDA to treat hair loss) decreases dihydrotestosterone levels, and thus DHT’s affect on hair follicles. Both affect the 5-alpha-reductase, an enzyme that leads to more DHT in the body.

What Does Science Say About Saw Palmetto for Hair Loss?

A study involving 28 women and 34 men with androgenic alopecia had subjects apply topical saw palmetto extract to their scalps for three months. Researchers reported a 35% increase in subjects' hair density and a 67% reduction in scalp sebum. Having an excessively oily scalp is a risk and contributing factor in hair loss.

Another study involving 10 men with androgenic alopecia who took saw palmetto for one year found that seven of the 10 subjects (70%) reported improvement in hair growth.

At the 13th Annual Meeting of the European Hair Research Society, doctors presented evidence that adding just 0.5 percent of saw palmetto extract to ketoconazole shampoo provided better results for people with pattern hair loss than ketoconazole shampoo without saw palmetto extract.

A comprehensive systematic review of research studies regarding saw palmetto for hair loss found the following results:

Use of topical lotions containing saw palmetto improved hair count in subjects after 10 weeks (17% improvement) and 50 weeks (27%). No adverse side effects were reported.
Hair thickness and hair mass improved significantly in another study involving adults with androgenic alopecia compared to a placebo. At 10 weeks, researchers reported a 20% improvement in hair mass and thickness. At 50 weeks, researchers reported a 30% increase in mass and thickness.
When one group was given oral supplements of saw palmetto and another group used finasteride daily for 24 months, researchers discovered that 52% of the saw palmetto group experienced "stabilization of androgenic alopecia."

In addition, chemical analysis of saw palmetto extract shows that the plant's phytochemicals consist of:

Sterols
Fatty acids
Carotenoids
Tannin
Beta sitosterol

All of these substances, especially beta sitosterol, are beneficial to hair regrowth due to androgenic alopecia. Included in the sterol compound group, beta sitosterol not only has anti-inflammatory properties but also seems to block DHT from disrupting the normal function of hair follicles.

Does Saw Palmetto for Hair Loss Cause Side Effects?

Saw palmetto in capsule or oral form has a higher likelihood of side effects compared to topical.

The most common side effects reported by individuals taking saw palmetto supplements in capsule form is stomach ache or nausea that may be relieved by eating something. However, saw palmetto is contraindicated for people taking certain medications.

Saw palmetto may interact adversely with the following medications:

Estrogen pills or patches (the anti-hormone effects of saw palmetto could counteract the ability of estrogen medications to increase estrogen in women)

Birth control pills/birth control implants (may decrease the effectiveness of birth control products containing estrogen)

Hormone replacement therapy products (some HRTs combine estrogen with progesterone. Saw palmetto may also prevent an HRT product from raising levels of both progesterone and estrogen)

Antiplatelet and anticoagulant drugs. (saw palmetto may increase bleeding risks in people who take warfarin, aspirin, NSAIDs and other blood-thinning medications for medical problems)

For topical saw palmetto, there’s the possibility that shampoos or lotions containing saw palmetto could irritate skin in people sensitive to one of the many phytochemicals found in plant leaves and fruit.

Adults who are considering saw palmetto oral supplements for treating medical conditions should always talk to their doctor about possible side effects and the safety of taking saw palmetto with other medications not mentioned here.

How Should You Take Saw Palmetto for Hair Loss?

We see this question a lot: should I take oral or topical saw palmetto for hair loss?

Do saw palmetto supplements grow hair?

Topical saw palmetto extracts and formulations containing these ingredients have demonstrated an ability to aid in hair growth, and because they’re topically applied, the risk of systemic issues is much lower. In fact, the safety of saw palmetto applied topically is precisely why Drs. Shapiro and Borenstein included this potent DHT fighting extract in their patented Shapiro MD Shampoo and Conditioner.

Saw palmetto capsules, meanwhile, are available at most pharmacies and department stores in the dietary supplement section. In adults taking between 320 mg and 960 mg daily for three years, no serious side effects have been reported.

A review of popular oral saw palmetto supplements finds:

Some saw palmetto supplements contain biotin to support hair health and growth. Supplements offering both saw palmetto and biotin might provide as much as 1000 mg of saw palmetto and 1000 mg of biotin. A lack of biotin can contribute to hair, skin, and nail problems. Biotin is necessary to activate cell growth, metabolize amino acids and fats, and create essential fatty acids in the body.
Saw palmetto capsules are often advertised as "DHT blockers" for men with prostate issues, and can contain 1200 mg of saw palmetto extract or more.
Capsules combining saw palmetto with a wide variety of herbal supplements are available for prostate health and even hair growth for men and women. Herbal additives include ashwagandha root, nettle leaf, green tea, maca root, and turmeric curcumin root, all of which are recognized for some sexual health claims.

Due to the unregulated nature of supplements and the fact that many of these ingredients are not FDA-approved, saw palmetto supplements taken by mouth may not be the first place you should look.

Find Out How Saw Palmetto Can Work For You

Our natural and patented Shampoo, Conditioner, and unique Foamers all contain saw palmetto alongside other DHT-fighting and hair-stimulating ingredients, like caffeine and EGCG. They were first developed over ten years ago as a hair loss solution for men and women in Dr. Shapiro’s clinical practice who wanted something easy to use that they could start immediately.

These formulas were designed for simplicity, to help people dealing with hair loss get thicker-looking, healthier hair at home.

If you're looking for natural hair loss formulations, Shapiro MD is a great plae to begin.