Differential effects of caffeine on hair shaft elongation, matrix and outer root sheath keratinocyte proliferation, and transforming growth factor‐β2/insulin‐like growth factor‐1‐mediated regulation of the hair cycle in male and female human hair folliclesin vitro

This study reveals new growth-promoting effects of caffeine on human hair follicles in subjects of both sexes at different levels (molecular, cellular and organ).