Hair Follicles – An Efficient Storage and Penetration Pathway for Topically Applied Substances

In the past, it was assumed that the intercellular route was the only relevant penetration pathway for topically applied substances. Recent results on follicular penetration obtained at the Center for Experimental and Applied Cutaneous Physiology, Charité - Universitätsmedizin Berlin, Germany, emphasize that the hair follicles represent a highly relevant and efficient penetration pathway and reservoir for topically applied substances.