Caffeine Linked to Hair Growth

LUBECK, GermanyScientists investigating androgenetic alopecia (AGA, hereditary hair loss) found testosterone applied to hair follicles impeded growth, while caffeine application spurred growth (Intl J Dermatol. 46, 1:27, 2007). Hair follicles from 14 biopsies were taken from the vertex (skull top) areas from male AGA patients. The samples were cultivated for 120 hrs. to 192 hrs. in vitro, with normal William's E medium (hair culture model) or William's E medium containing different concentrations of testosterone and/or caffeine. Hair shaft elongation was measured daily and at the end of cultivation; cryosections of follicles were stained with Ki-67 to evaluate the degree and localization of keratinocyte proliferation.

Results showed significant growth suppression in hair follicles treated with 5 µg/ml testosterone. This was counteracted by caffeine in concentrations of 0.001 percent and 0.005 percent. Moreover, caffeine alone led to a significant stimulation of hair follicle growth. These results were confirmed immunohistochemically by Ki-67 staining.

The researchers concluded caffeine was identified as a stimulator of human hair growth in vitro, a fact which may have important clinical impact in the management of AGA.