>>508165744Pharmafag here.
So, male pattern baldness is actually just androgenic alopecia. Androgenic alopecia is present to widely varying degrees in all humans, male or female.
Essentially, the main culprit is a hormone called dihydrotestosterone (DHT). DHT causes scalp hair to miniaturize. Note that other androgens cause scalp hair to miniaturize as well, but it's not well understood to what degree, it's thought to be much less than DHT.
Regardless, in order to slow down androgenic alopecia, you have to stop DHT from binding to receptors in the scalp. There's really no way that we know to selectively block DHT only in the scalp. Instead, we use 5 alpha reductase inhibitors like finasterise to stop the conversion of testosterone into DHT.
There's issues with this though, since we don't want to block this too much because we don't really understand DHT's role in adults. During puberty DHT is primarily responsible for secondary sexual characteristics like beard growth, voice deepening, bone density, penis growth, etc. This is why it's abhorrent to use finasteride to block puberty, it's essentially needed for men to be "men".
In adult males, it's MUCH less problematic but still can cause many issues. Going bald tends to cause many issues also, so its definitely something that needs to be weighed. Personally, I wouldn't touch finasteride until I was at the very least 28.
Personally, I have been using it for years at 0.5mg weekly. This has essentially stopped my hair loss with minimal side effects. No one should be taking finasteride daily. 0.5 mg dose cuts DHT conversion roughly in half for a week.
Anyway, this was my autistic blog post. As always, don't be a free agent in life anons.