Why are Hair loss drugs a lot more effective on Apes?

Does anyone know the reason why all these hair loss drugs work 10x better in apes/monkeys that have hair loss and not as well on humans.

I wanna assume it has something to do with their diet. I'm sure even apes kept in labs are fed bananas or whatever else they'd naturally eat. Whereas humans in studies are just guys who agreed to test.

I believe it has to do with them having a higher follicle density than humans. I believe humans have 2-3 hairs per follicle while apes have 5-6. Each hair supports one another while growing, more hair equals more/faster regrowth. This is also why we get bald spots; once one goes dormant the surrounding ones become affected as well and it slowly spreads out.

Also, this is why the mice in the astressin-b trial regrew their hair so quickly, I believe they have 7-10 per follicle.

Its late for me so I hope that made sense.