system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: does Rogaine work, and if so, how?
gpt
Interesting story. Science isn't perfectly clear on the why/how.

Minoxidil (Rogain) is a [edit: *anti*hypertensive] ~~hypetensive~~ (high blood pressure) drug, and they discovered the hair growth as a side effect of prescribing it for high blood pressure. They think that maybe the drug widens blood vessels and opening potassium channels which allows more oxygen, blood, and nutrients to the hair follicles.  And, yes it often does work, for Male Pattern Baldness, especially in younger men who have only begun to show the balding pattern.  If you've been bald for a long time it doesn't work as well (or maybe not at all).

also, as an interesting side fact, in even small quantities, it's FATAL to cats.