I am 22 and am thinning on the top, back and sides of the head

If you have thinning along the sides and back of your head as well as elsewhere (thinning on front and top), there is a condition we published called Diffuse Unpatterned Alopecia (DUPA) which requires a doctor to make the diagnosis with a hand microscope showing miniaturization in the sides and back of the head hair.This is a difficult problem to treat and people like you who have DUPA are not candidates for hair transplantation.