Can Saw Palmetto Halt Hair Loss?

Saw Palmetto Serenova repens
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If you've been reading about natural remedies for hair loss, you may have come across a herb called saw palmetto. Sourced from the berries of a North American plant known as Serenoa repens or Sabal serrulata, saw palmetto extracts are said to help slow or reduce the type of hereditary hair loss known as androgenic alopecia (a common form of hair loss also known as male- or female-pattern baldness).

Saw palmetto is sometimes touted as a natural treatment for other health conditions, such as acne, benign prostatic hyperplasia (BPH), erectile dysfunction (ED), and polycystic ovary syndrome (PCOS).

The Benefits of Saw Palmetto for Hair Loss: Does It Really Work?

One theory on how saw palmetto might work is that it could 5-alpha-reductase, an enzyme involved in the conversion of the hormone testosterone to dihydrotestosterone (DHT). DHT is considered a key contributing factor to the onset and progression of androgenic alopecia. It is also said to increase the activity of an enzyme responsible for the metabolism of DHT into androstanediol (a weaker androgen hormone).

Much of saw palmetto's popularity as a remedy for hair loss and baldness is based on how it is believed to work rather than on research. Although there is some laboratory research suggesting that saw palmetto has the potential to inhibit 5-alpha-reductase, there is a lack of well-designed clinical trials showing that saw palmetto can cause hair regrowth or stop the progression of hair loss.

The available research includes an open label study published in the International Journal of Immunopathology and Pharmacology in 2012. Of the 100 men with mild to moderate androgenic alopecia, one group took 320 mg of saw palmetto daily for 24 months, and the other group took 1 mg finasteride (a medication used for hair loss) daily for the same period.

The researchers found that the hair growth score was higher in the group that received finasteride compared to the saw palmetto group, and that the effect of saw palmetto was inferior to that of finasteride. 

In a study published in the Journal of Alternative and Complementary Medicine in 2002, 26 men with mild to moderate androgenic alopecia took a supplement containing saw palmetto and beta-sitosterol or a placebo for 21 weeks. Treatment effectiveness at the final visit, assessed by staff, was reported to be 60 percent in the saw palmetto group compared to 11 percent in the placebo group. Side effects were mild and transient.

Possible Side Effects

As with other herbal supplements, little is known about the side effects of long-term use or high doses of saw palmetto. Side effects are usually mild. Stomach pain, constipation, diarrhea, nausea, and vomiting have been reported. Some men have reported sexual dysfunction.

There is some concern that saw palmetto could cause liver, pancreatic, or cardiac problems in some people.

There have been reports of liver injury and pancreatitis in people taking saw palmetto, however there isn't enough information to know whether saw palmetto was the true cause of the adverse reactions.

Although it hasn't been well-demonstrated in humans, saw palmetto may influence levels of sex hormones such as estrogen and testosterone. Until we know more, people with hormone-sensitive conditions, such as breast cancer, should avoid it. Also, saw palmetto could theoretically interfere with oral contraceptives and hormone therapy, and may work in a similar manner to the medication finasteride. 

Children and pregnant or nursing women shouldn't take saw palmetto.

Saw palmetto could slow blood clotting. People with bleeding disorders or who are taking anticoagulant or antiplatelet medications or supplements, such as warfarin (Coumadin®), aspirin, or clopidogrel (Plavix®), should avoid taking saw palmetto unless under medical supervision. It should also be avoided at least two weeks before and after surgery.

It's important to keep in mind that supplements haven't been tested for safety and dietary supplements are largely unregulated. You can get further tips on using supplements here

Using Saw Palmetto

If you're considering using saw palmetto, be sure to consult your healthcare provider to discuss whether it's appropriate for you.


Prager N, Bickett K, French N, Marcovici G. A randomized, double-blind, placebo-controlled trial to determine the effectiveness of botanically derived inhibitors of 5-alpha-reductase in the treatment of androgenetic alopecia. J Altern Complement Med. (2002) 8.2: 143-152.

Rossi A, Mari E, Scarno M, et al. Comparitive effectiveness of finasteride vs Serenoa repens in male androgenetic alopecia: a two-year study. Int J Immunopathol Pharmacol. 2012 Oct-Dec;25(4):1167-73.

Ulbricht C, Basch E, Bent S, Boon H, Corrado M, Foppa I, Hashmi S, Hammerness P, Kingsbury E, Smith M, Szapary P, Vora M, Weissner W. Evidence-based systematic review of saw palmetto by the Natural Standard Research Collaboration. J Soc Integr Oncol. (2006) 4.4: 170-186.

Wessagowit V, Tangjaturonrusamee C, Kootiratrakarn T, Bunnag T, Pimonrat T, Muangdang N, Pichai P. Treatment of male androgenetic alopecia with topical products containing Serenoa repens extract. Australas J Dermatol. 2016 Aug;57(3):e76-82.

Wilt TJ, Ishani A, Stark G, MacDonald R, Lau J, Mulrow C. Saw palmetto extracts for treatment of benign prostatic hyperplasia: a systematic review. JAMA (1998) 280.18: 1604-1609.

Disclaimer: The information contained on this site is intended for educational purposes only and is not a substitute for advice, diagnosis or treatment by a licensed physician. It is not meant to cover all possible precautions, drug interactions, circumstances or adverse effects. You should seek prompt medical care for any health issues and consult your doctor before using alternative medicine or making a change to your regimen.

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