Caffeine and Hair: What does Caffeine do for Hair?

What does caffeine do for hair?

This specialty coffee reminded me about the increasing attention recently on topical (not oral) caffeine for hair growth. Topical caffeine is slowly catching the attention of the hair world and general public. A small number of studies have suggested that caffeine may have positive effects on hair follicles when applied topically. Some shampoos are even including caffeine additives with “claims” it reduces shedding.

I’m reminded of a 2014 study which set out to investigate the impact of caffeine on hair growth in vitro and to better understand how caffeine modulates the effects of testosterone.

The researchers used microdissected human scalp hair follicles (both male and female) and treated them in culture with testosterone or the combination of testosterone and caffeine). Remarkably, caffeine prolonged anagen duration, enhanced hair shaft elongation and stimulated hair matrix keratinocyte proliferation. Hair follicles from men were less sensitive to caffeine than female follicles.

Caffeine had effects on TGF-β2 and IGF-1. Specifically, caffeine blocked testosterone-enhanced TGF-β2 protein expression in male HFs. In female HFs, caffeine reduced TGF-β2 expression. IGF-1 protein expression was upregulated in both male and female hair follicles.

I have read and reread this study a few times over the years. It’s quite interesting that caffeine has hair growth promoting properties.

The use topical caffeine for its effects on hair is still in its early days. There are several commercially available products that contain caffeine (mainly shampoos) and a few of these shampoos have small clinical studies that show some potential to reduce shedding and improve the look of the hair. These studies are small and preliminary in nature.

Government regulators in some countries have recently come down hard on manufacturers of “caffeine” containing hair products (especially some shampoo makers) scrutinizing claims that these products benefit hair. More rigorous studies are needed to determine definitively what role these products have.
 

Reference

Fischer TW, et al. Br J Dermatol. 2014. and Sisto et al J Appl Cosmetol 2013