Historically, women have been seen (medically) as just smaller men. The tests I'm talking about were to determine side-effects, not effectiveness of the medication. So while hair removal is for people with hair, you can still test on Patrick Stewart to see if there's going to be chemical burns. But because it's medication, and was mostly tested on white men, BIWOC were left mostly untested and are more likely to experience complications and different side-effects.

Scientists just started this year (or last year I forget) using actual blood to test period products. They used colored water before. Our medical system has systematically left women to figure shit out on their own.