Saw palmetto (Serenoa repens) is a type of palm native to the southeastern United States.
The berries of the plant are commonly used in supplements to improve prostate health, balance hormone levels, and prevent hair loss in men.
It’s also associated with other benefits, including decreased inflammation and improved urinary function.
Here are 5 promising benefits and uses of saw palmetto.
1. Prevents hair loss
Hair loss is a common condition that can be caused by a variety of factors, including genetics, certain medical conditions, hormonal changes, and the use of medications, such as stimulants and blood thinners.
Saw palmetto is often used to balance hormone levels and combat hair loss.
According to one review, saw palmetto may help block the activity of 5-alpha reductase (5α-R), an enzyme that converts testosterone into a hormone linked to hair loss called dihydrotestosterone (DHT).
It may also prevent hair loss by reducing the uptake of DHT in the hair follicles, which decreases its ability to bind to specific hormone receptors.
In one study, saw palmetto was effective at improving hair growth in 60% of men with male pattern baldness between the ages of 23 and 64.
Another study in 62 adults showed that applying saw palmetto topically for 3 months increased hair density by 35%.
2. Improves urinary tract function
Urinary tract symptoms are common among older men and can include issues like incontinence and difficulty urinating.
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.
One 12-week study in 92 men showed that taking two capsules daily of Prostataplex, a mix of herbal supplements that include saw palmetto, helped improve urinary tract symptoms associated with BPH.
Similarly, another study in 85 men over the age of 45 found that treatment with 160 mg of saw palmetto twice daily reduced lower urinary tract symptoms, increased urine flow, and improved overall quality of life after 6 months.
However, more research is needed to determine whether saw palmetto may also improve urinary tract function in the general population, including for those without prostate issues.
3. May support prostate health
The prostate is a small gland located between the bladder and the penis in men, which is responsible for maintaining sperm health.
Some research suggests that saw palmetto could support prostate health and may aid in preventing issues like BPH and prostate cancer.
According to one test-tube study, saw palmetto berry extract was able to decrease the growth of prostate cancer cells.
Another test-tube study showed that saw palmetto blocked the spread and growth of prostate cancer cells by deactivating specific receptors involved in cancer development.
Other human and animal studies indicate that it may be effective at reducing urinary symptoms and inflammation related to BPH as well.
Yet, some studies don’t associate saw palmetto with a lower risk of prostate cancer and observe that it may be ineffective at decreasing symptoms of BPH.
Further high-quality research is needed to evaluate how saw palmetto may affect prostate health in humans.
4. May decrease inflammation
Saw palmetto contains the antioxidants epicatechin and methyl gallate — compounds that prevent damage to cells, decrease inflammation, and protect against chronic disease.
Some research shows that saw palmetto may have anti-inflammatory properties, which could be beneficial in treating certain conditions.
For example, one study observed that giving saw palmetto extract to mice with enlarged prostate glands decreased swelling and several markers of inflammation, including interleukin 6 (IL-6).
Another study in obese rats with BPH found that saw palmetto was effective at decreasing inflammation and improving antioxidant status.
Although these results are promising, additional studies are needed to determine how saw palmetto may impact inflammation in humans.
5. May help regulate testosterone levels
Saw palmetto is often used by men looking to boost testosterone levels naturally.
Regulating testosterone levels can impact several aspects of health, including body composition, sex drive, mood, and cognition.
Testosterone levels decline with age, and some research shows that low levels of testosterone could contribute to conditions like heart disease.
Saw palmetto works by decreasing the activity of 5α-R — an enzyme responsible for converting testosterone to dihydrotestosterone (DHT), another sex hormone, to help preserve testosterone levels in the body.
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 5α-R.
Another study in 40 men observed that treatment with saw palmetto decreased levels of DHT by 32% after 6 months, suggesting that saw palmetto was effective at maintaining testosterone levels.