What Does Saw Palmetto Do for Your Hair?

Saw palmetto is an herbal extract that many men may already be familiar with; it's the main ingredient in prostate supplements. Maintaining normal urinary patterns is important to men as they age—but, it's not their only concern; many also worry about keeping that full head of hair.

Fortunately, some new research suggests that the same nutrient that supports prostate health may help men (and women, too!) maintain youthful, healthy tresses long into their golden years.

What is saw palmetto?

Saw palmetto is an herb that comes from a small, fan-shaped plant called Serenoa repens, which you'll find all over the southeastern United States. Its cholesterol-like-compounds (such as beta-sitosterol, which functions as a structural component to the cell membranes in plants) serve a purpose in humans as well.

The health benefits of saw palmetto really do make it man's best friend and a top supplement choice: in addition to promoting urinary and prostate health, it also may support healthy testosterone levels. Saw palmetto also contains antioxidants that promote a healthy inflammatory response.

What are the benefits of saw palmetto for hair?

To describe the hair benefits of saw palmetto you first must understand how the hair growth cycle works. There are four phases:

• Anagen

  : The growth phase, which can last for many years.

• Catagen

  : When the hair becomes unattached from the root of the hair follicle.

• Telogen

  : This is the resting phase, in which the hair follicle lies dormant for a few months.

• Exogen

  : Next comes the shedding phase, when hairs fall out—after which the anagen phase restarts with a new hair.

But sometimes these phases don't happen like clockwork. The anagen or growth phase can get shorter, while the telogen phase or resting phase can get longer. If you want to keep your hair healthy and youthful looking, you can't let that growth phase take too long of a break. Research shows that saw palmetto can support healthy levels of the hormone dihydrotestosterone (DHT), the hormone involved in the exogen phase—so, your hair growth cycle won't "slack off" for too long.

Put simply, saw palmetto is like a parent that provides space for its kids (our head hair) to grow up, but also kicks them out of bed when they're sleeping in too late!

Testosterone and hair growth: What is the connection?

Why does hair get a little "sleepy" during the growth phase? It may be due to levels of DHT, a derivative of testosterone that is created when an enzyme called 5-alpha reductase acts upon it. Saw palmetto helps inhibit levels of 5-alpha reductase, which can in turn promote healthy DHT levels. As a result, you can end up with longer hair growth phases (anagen) and shorter hair resting (telogen) phases.

DHT blood testing is a great way to check in on your levels of this type of testosterone—conveniently, it also will let you know how your prostate is functioning.

Saw palmetto: Topical vs oral supplements

Should you take saw palmetto supplement, or apply it to your hair directly? Oral saw palmetto was shown in a small randomized, double-blind, placebo-controlled trial to have an improvement in head hair quality in 60% of the trial participants over the course of 25 weeks—in addition to other benefits to men's health. Looking at hair health alone, topical application had even more impressive results: in a study on men, there was a 74.1% increase in thick, long head hair at 24 weeks. But, there weren't any other health benefits found in this study.

References

• Boyle, P et al. "Updated meta-analysis of clinical trials of Serenoa repens extract in the treatment of symptomatic benign prostatic hyperplasia." BJU Int., April 2004, https://pubmed.ncbi.nlm.nih.gov/15049985/
• Dhariwala, Maria Yusuf, and Padmini Ravikumar. Journal of Cosmetic Dermatology vol. 18,4 (2019): 966-975.
• Evron, Evyatar et al. "Natural Hair Supplement: Friend or Foe? Saw Palmetto, a Systematic Review in Alopecia." Skin Appendage Disord., November 2020, https://pubmed.ncbi.nlm.nih.gov/33313047/
• Pais, Pilar et al. "Determination of the potency of a novel saw palmetto supercritical CO2 extract (SPSE) for 5α-reductase isoform II inhibition using a cell-free in vitro test system." Res Rep Urol., April 2016, https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC4847595/
• Sudeep, H V et al. "A double blind, placebo-controlled randomized comparative study on the efficacy of phytosterol-enriched and conventional saw palmetto oil in mitigating benign prostate hyperplasia and androgen deficiency." BMC Urol., July 2020, https://pubmed.ncbi.nlm.nih.gov/32620155/
• Strum, Stephen B. "Serenoa Repens (Saw Palmetto) for Lower Urinary Tract Symptoms (LUTS): The Evidence for Efficacy and Safety of Lipidosterolic Extracts. Part III." Uro., August 2021, https://www.mdpi.com/2673-4397/1/3/17/htm
• Tacklind, James et al. "Serenoa repens for benign prostatic hyperplasia." Cochrane Database Syst Rev., December 2012, https://pubmed.ncbi.nlm.nih.gov/23235581/
• Ustuner, Emin Tuncay. "Cause of androgenic alopecia: crux of the matter." Plast Reconstr Surg Glob Open., November 2013, https://pubmed.ncbi.nlm.nih.gov/25289259/
• Van Deelen, Timothy R. et al. "Serenoa repens. In: Fire Effects Information System," U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, October 2021. https://www.fs.fed.us/database/feis/plants/shrub/serrep/all.html
• Yun, Jeong Moon et al. "Standardized Saw Palmetto Extract Directly and Indirectly Affects Testosterone Biosynthesis and Spermatogenesis." J Med Food., June 2021, https://pubmed.ncbi.nlm.nih.gov/34161166/
• "Hair Loss: The Science of Hair" WebMD, 2010. https://www.webmd.com/skin-problems-and-treatments/hair-loss/science-hair