Got horny from Finasteride, why is that?

I went to my dermatologist because I’ve also been dealing with diffuse thinning on my scalp. Very aggressively lately. He told me about finasteride and gave me 300 tablets. I’ve been on them for 3 weeks now. In the first week, my libido went up a lot. From zero to feeling horny almost every single day. Kinda like my old self. Now, I did some research… and I know this is common...

Source