HAIR-GROWTH-PROMOTING AGENTS IN ANDROGENE TIC ALOPECIA - EXPECTATIONSAND REALITY

Androgenetic hair loss is the most frequent reason for the topical app lication of hair-growth-promoting agents. Such preparations should arr est or even reverse androgen-induced hair follicle regression as well as prolonging the hair cycles, especially of the shortened anagen phas e, and thus protect from increased hair loss. True evidence of drug ef fects on hair growth is problematic, since trichograms, the method chi efly applied by the manufacturers, fail to reveal every factor involve d in the follicular activity, especially the duration of anagen stage. For example, an increase in the anagen rate does not always reflect a lengthening of the anagen stage, but may also be due to shortened hai r cycles. Accordingly, drug effects on hair growth should be investiga ted by methods that analyse the cell cycle kinetics. For this approach DNA-flowcytometry of the outer root sheath in plucked anagen hairs an d of complete anagen hair bulbs taken by micropreparative techniques f rom scalp biopsies offers a reproducible method for quick and reliable evaluation of hair growth.