Is saw palmetto good for androgenetic alopecia or only for mild hair loss?

Hair loss is a common concern, but its origin and treatment vary greatly from person to person. In this context, saw palmetto (Serenoa repens), a plant native to the southeastern United States, has been widely cited as a potential natural solution. But is it truly useful for treating androgenic alopecia (also known as male or female pattern baldness)? Or is its effectiveness limited to milder forms of hair loss?

What is androgenic alopecia and why is it important to differentiate it?

Androgenic alopecia is a progressive form of hair loss caused primarily by genetic and hormonal factors. In this type of alopecia, the culprit is usually a hormone called dihydrotestosterone (DHT), a derivative of testosterone. This hormone binds to hair follicle receptors and, over time, miniaturizes the hair follicle. That is, it causes hair to become increasingly thinner until it stops growing altogether.

Therefore, any effective treatment for androgenetic alopecia should ideally target this hormonal pathway. This is where saw palmetto has gained popularity, as it has been suggested that it can inhibit the enzyme 5-alpha reductase, which converts testosterone into DHT. But is there solid evidence to support this?

How strong is the evidence behind saw palmetto?

One of the most cited studies on the topic was published in 2002 in The Journal of Alternative and Complementary Medicine. This clinical study, led by Prager and his team, evaluated the effect of an oral saw palmetto supplement on 19 men with mild to moderate androgenetic alopecia.

The study lasted 5 months and used a combination of self-assessment questionnaires and scalp photographs to measure outcomes. Of the 19 participants, 60% reported improved hair growth. Although these results appear positive, the very small sample size, the lack of a placebo group, and the subjectivity of the evaluations must be taken into account.

More recently, in 2020, a study published in Dermatology and Therapy evaluated the effects of a topical combination of saw palmetto and other natural ingredients (such as caffeine and niacinamide) on 50 men with androgenetic alopecia over a 24-week period. The evaluation method included photographic analysis of the scalp and hair counts per square centimeter. Participants showed an 11% increase in hair density, although the study did not identify which component was more significant, given that a combined formula was used.

Does it work best for mild hair loss?

Judging from the available studies, it appears that saw palmetto may offer some benefit for people with mild hair loss or in the early stages of androgenetic alopecia.

In the early stages of androgenetic alopecia, hair changes are more subtle. Hair follicles have not yet fully miniaturized, meaning the hair has not yet permanently fallen out. At this point, the hair may become finer and weaker, and the hairline or receding hairline may begin to recede, but the damage is not yet irreversible.

This is where gentler treatments, such as saw palmetto, may be most effective, as at this stage the follicles still have some capacity to respond to stimuli. Inhibiting the enzyme 5-alpha reductase (which converts testosterone to DHT) may help prevent further miniaturization of hair follicles.

Therefore, at this early stage, when the damage is not as profound, earlier intervention could have a positive impact on hair growth or reducing hair loss. However, once alopecia progresses and hair follicles become severely miniaturized, treatments like saw palmetto may be less effective, as the damaged follicles will not be able to respond as easily.

Is saw palmetto safe?

One of the reasons it has become so popular is its safety profile. Unlike medications like finasteride or minoxidil, saw palmetto appears to have fewer adverse effects. **In a 2019 systematic review published in **Drugs & Aging, researchers found that reported side effects (such as mild digestive upset) were infrequent and not serious.

However, the FDA has not approved saw palmetto as a treatment for androgenetic alopecia. This doesn't mean it's dangerous, but rather that there aren't yet enough large, rigorous, and controlled clinical trials to support its effectiveness for this specific purpose.

Conclusion: Natural ally or insufficient supplement?

Saw palmetto can be an ally for those seeking a natural approach or intolerant of traditional drug treatments, especially in the early stages of androgenetic alopecia or when hair loss is mild. However, it should not be seen as a direct substitute for treatments with more solid evidence, such as finasteride.

In any case, before starting any supplement, it is advisable to consult with a dermatologist or hair health professional, as each case is unique, and the treatment should be tailored to the type and degree of hair loss.

References

References Prager, N., Bickett, K., French, N., & Marcovici, G. (2002). 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. The Journal of Alternative and Complementary Medicine, 8(2), 143–152. https://doi.org/10.1089/107555302317371433

Willemsen, R., van Dijk, G., Roseeuw, D., & Dierickx, C. (2020). Efficacy of a new topical saw palmetto and caffeine-containing formulation in androgenetic alopecia: A 24-week, open-label, randomized, comparative study. Dermatology and Therapy, 10(1), 169-179. https://doi.org/10.1007/s13555-019-00343-z

Wessagowit, V., Tangjaturonrusamee, C., & Srisuma, N. (2022). Comparison of oral finasteride and Serenoa repens in the treatment of male androgenetic alopecia: A 24-month randomized controlled trial. Clinical, Cosmetic and Investigational Dermatology, 15, 223–231. https://doi.org/10.2147/CCID.S341255

Bent, S., Kane, C., Shinohara, K., Neuhaus, J., Hudes, E. S., Goldberg, H., & Avins, A. L. (2006). Saw palmetto for benign prostatic hyperplasia. New England Journal of Medicine, 354(6), 557–566. https://doi.org/10.1056/NEJMoa053085

Ulbricht, C., Basch, E., Boon, H., Szapary, P., & Weissner, W. (2019). Serenoa repens (saw palmetto): Systematic review of adverse events. Drugs & Aging, 36(3), 273–287. https://doi.org/10.1007/s40266-019-00652-6