Caffeine’s Mechanisms of Action and Its Cosmetic Use

The 2012 document reviews caffeine's role in cosmetics, highlighting its ability to penetrate the skin and its benefits in reducing cellulite, enhancing microcirculation, acting as an antioxidant, and stimulating hair growth. Caffeine prevents fat accumulation and promotes fat degradation by inhibiting phosphodiesterase, which increases cAMP in cells. It protects against UV radiation, potentially preventing UV-induced skin cancers by scavenging radicals and inducing apoptosis in damaged cells. Studies cited include one with a 7% caffeine solution reducing cellulite and another testing a 3% caffeine gel for eye puffiness, though without significant results. Caffeine also inhibits 5-a-reductase, which may help manage androgenetic alopecia, and can remain in hair follicles for up to 48 hours post-shampoo application. The document suggests caffeine's cosmetic potential is significant but calls for further research on dosing, delivery systems, and potential side effects.