In 47 healthy volunteers betamethasone-17-valerate (0.1% solution and cream) was topically applied twice daily on the scalp skin. After 7 and 14 days treatment, anagen hairs were plucked in each volunteer from both treated and untreated contralateral scalp areas. Cell cycle analysis of plucked anagen hairs was performed by means of DNA flow cytometry. Already after topical betamethasone-17-valerate application for 7 days, cell kinetic changes were found showing a slightly significant decrease of S and G2 + M cell percentages and a significant increase of G0/1 cell percentages. The present study demonstrates the possibilities of DNA flow cytometry to study the pharmacological effects on cell kinetics of plucked human anagen hairs.