182 citations
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December 2007 in “BJCP. British journal of clinical pharmacology/British journal of clinical pharmacology” Hair follicles significantly increase the speed and amount of caffeine absorbed through the skin.
153 citations
,
October 2012 in “Skin Pharmacology and Physiology” Caffeine in cosmetics may reduce cellulite, protect skin, and stimulate hair growth, but more research is needed on its use and effects.
114 citations
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January 2007 in “International Journal of Dermatology” Caffeine can stimulate hair growth and counteract testosterone's suppressive effects on hair follicles.
93 citations
,
January 2007 in “Skin Pharmacology and Physiology” Caffeine in shampoo quickly enters the body through hair follicles.
82 citations
,
May 2009 in “BJCP. British journal of clinical pharmacology/British journal of clinical pharmacology” Caffeine penetrates human skin in lab tests similarly to real-life conditions, but actual skin use is still essential for accurate results.