Saw Palmetto

If you’re coping with common concerns such as prostate issues or hair loss, you may wonder whether any natural supplements will help. Saw palmetto (Serenoa repens), a type of palm native to the southeastern United States, is commonly used in supplements to improve prostate health, balance hormone levels, and prevent hair loss in men. Plus, it’s associated with a variety of other benefits, including decreased inflammation and improved urinary function.

Here are 5 promising benefits and uses of saw palmetto, along with some key risks and side effects.

 

May Prevent Hair Loss

Hair loss is a common condition that can be caused by a variety of factors, including genetics, certain medical conditions, hormone changes, and the use of medications such as stimulants and blood thinners (1).

Saw palmetto is often used to balance hormone levels and combat hair loss.

According to one study, saw palmetto may help block the activity of 5-alpha reductase, an enzyme that converts testosterone into another sex hormone called dihydrotestosterone (DHT) that is linked to hair loss (2).

Saw palmetto may also prevent hair loss by reducing the uptake of DHT in your hair follicles, which decreases DHT’s ability to bind to specific hormone receptors (2).

One review of 7 studies found that oral and topical supplements containing saw palmetto improved hair quality by 60%, raised total hair count by 27%, and increased hair density in 83% of people with hair loss (3). 

Even though some study results suggest that saw palmetto may have beneficial effects on hair growth, more research is needed (4).

 

May Improve Urinary Tract Function

Urinary tract symptoms such as incontinence and difficulty urinating are common among older adults (5).

Saw palmetto may improve urinary symptoms associated with benign prostate hyperplasia (BPH), a condition that causes an enlargement of the prostate gland and results in decreased urine flow.

In one small 12-week study, men who took 1,000 mg daily of saw palmetto oil enriched with beta-sitosterol, a compound found naturally in many plants, experienced significant improvements in BPH symptoms compared with those who took unenriched saw palmetto oil (6).

Similarly, a 24-week study in 354 men found that taking 320 mg of saw palmetto decreased symptoms of BPH and improved urinary flow, quality of life, and sexual function compared with a placebo (7).

On the other hand, a recent review of 27 studies concluded that saw palmetto had no significant impact on lower urinary tract symptoms when used alone (8).

 

May Support Prostate Health

The prostate is a small gland located between the bladder and the penis. It’s responsible for maintaining sperm health (9).

Some research suggests that saw palmetto can support prostate health and help prevent issues such as BPH and prostate cancer (10).

Other human and animal studies also indicate that this supplement may reduce urinary symptoms and inflammation related to BPH (7, 11, 12).

What’s more, a 15-year study in 30 men concluded that taking 320 mg of saw palmetto extract daily may help prevent the progression of BPH (13).

Yet some studies don’t associate saw palmetto with improvements in prostate health or BPH symptoms (8).

 

May Decrease Inflammation

Some research suggests that saw palmetto has anti-inflammatory properties, which may help treat certain conditions.

For example, one study in mice with enlarged prostates observed that saw palmetto extract decreased swelling and several markers of inflammation, including interleukin 6 (IL-6) (12).

Another study in rats with BPH found that saw palmetto decreased inflammation and improved antioxidant status (14).

Although these results are promising, human studies are lacking.

 

May Help Regulate Testosterone Levels

Saw palmetto is often used by people looking to naturally boost testosterone levels.

Testosterone levels affect several aspects of health, including body composition, sex drive, mood, and brain function. Levels decline with age, and some research suggests that low levels contribute to health conditions such as heart disease (15, 16).

Saw palmetto works by decreasing the activity of 5-alpha reductase — an enzyme responsible for converting testosterone to DHT — to help preserve testosterone levels (2).

One test-tube study found that the effectiveness of saw palmetto extract was comparable to finasteride in preserving testosterone levels. Finasteride is a medication used to treat hair loss and BPH by reducing the activity of 5-alpha reductase (2).

According to one review, saw palmetto may help block the uptake of DHT and decrease its ability to bind to androgen receptors by nearly 50%. In turn, this may help regulate testosterone levels (3).

One 14-day study also noted that taking 1,200 mg per day of Resettin — a supplement made with saw palmetto and astaxanthin, a type of antioxidant found in algae — increased serum testosterone levels by 38% compared with a placebo (17).

Furthermore, a study in rats showed that saw palmetto increased testosterone synthesis, muscle endurance, and sperm count by altering hormone regulation (18).

 

How Does Saw Palmetto Work?

The active compounds in saw palmetto are believed to help block the activity of 5-alpha reductase, an enzyme responsible for converting testosterone to DHT (19).

This process may help maintain testosterone levels as you get older, which may lead to improvements in body composition, libido, and mood (15).

Because DHT is also involved in the enlargement of the prostate gland, decreasing your levels of DHT by using saw palmetto may also improve prostate health and BPH (20).

Furthermore, saw palmetto may help support hair health, as DHT regulates hair growth and may contribute to hair loss and balding (21).