Percutaneous Absorption of Minoxidil in Humans

The study aimed to determine the extent of percutaneous absorption of minoxidil in humans. The results showed that topically applied minoxidil is poorly absorbed through the skin, with only 1.6% to 3.9% of the applied dose being absorbed. The study also found that the scalp is not as permeable as previously thought. The data allowed for an estimation of the magnitude of minoxidil absorption under various clinical conditions, and it was concluded that applications of minoxidil at a 1% to 2% concentration to 50% of the scalp or less are unlikely to cause systemic side effects. The study did not find any adverse reactions or substantial laboratory abnormalities in the subjects during the study.