Rogaine (minoxidil) was originally developed as an anti-ulcer then anti-hypertensive medication.
https://www.researchgate.net/publication/289021851_How_minoxidil_was_transformed_from_an_antihypertensive_to_hair-loss_drug
As I recall, the scientist doing the BP work noticed the hair on his arms was growing with exposure to the drug.
Very interesting.