MINOXIDIL AND SWIMMING: HOW LONG DO I HAVE TO WAIT?
QUESTION: I am an avid swimmer. I swim every night and the club. I just started minoxidil. How long do I need to wait before swimming to ensure the medication went into my scalp?
Please wait at least 4 hours!
In general, one needs to leave minoxidil on the scalp at least 4 hours (and ideally 6-8 hours) in order for it to have any effect. 50 % of the drug is absorbed by 1 hr, and 75% by around 4 hrs. If you go swimming too soon, it simply gets washed off. One needs to find a time during the day where they can leave it on the scalp for many hours.
Jeff Donovan MD PhD FRCPC FAAD
US & Canadian board-certified Dermatologist
MEDICAL REFERENCE OF INTEREST
1. Ferry JJ et al. Relationship between contact time of applied dose and percutaneous absorption of minoxidil from a topical solution. J Pharm Sci. 1990 Jun;79(6):483-6.