Androgenetic alopecia (AGA), also known as congenital hair loss, is characterized by the progressive thinning and subsequent loss of hair on the head. AGA usually occurs around the age of 20; by the age of 50, almost 50% of all men are affected. This widespread dermatological phenomenon affects both men and women and usually has a negative impact on the quality of life of those affected.

Recent studies and investigations have shown positive effects of caffeine on hair growth in people suffering from congenital hair loss. These studies suggest that caffeine counteracts the reduction in hair follicle size caused by DHT (dihydrotestosterone) by inhibiting phosphodiesterase. This process increases the levels of cAMP in the cells and also increases cell proliferation by stimulating their cell metabolism.

The underlying study used the hair organ culture model (HOKM) to investigate the effects of testosterone and caffeine on the stimulation of hair follicle growth. As part of this in vitro study, biopsy samples were taken from the scalp of men suffering from androgenetic hair loss and exposed separately to different concentrations of testosterone and caffeine in the HOKM for a period of 120 to 192 hours. It was found that a concentration of 0.001% and 0.006% caffeine counteracted the hair growth-suppressing effects of testosterone. Compared to the control group, a higher increase in length (so-called “elongation”) of the hair shaft was observed after 120 hours under the influence of caffeine. Furthermore, in a test section in which caffeine and testosterone were simultaneously present in the nutrient solution of the HOKM, it was shown that caffeine was able to cancel out the negative effects of testosterone and even stimulated hair growth beyond the normal level. This is a clear demonstration of the hair growth-promoting properties of caffeine.

The positive effects of topical application of caffeine in the presence of AGA can therefore be attributed to the inhibition of phosphodiesterase, the improvement of the skin’s barrier function, follicle penetration and the stimulation and promotion of hair growth.

Conclusion

In terms of dealing with hereditary hair loss, caffeine has proven to be a very suitable and clearly hair growth-promoting active ingredient.

Underlying study:

Bansal, M. et. al: Fischer; T. W. et al: Effect of caffeine and testosterone on the proliferation of human hair follicles in vitro; in: International Journal of Dermatology 2007, January; 46(1):27-35.