Well I take sustanon every week, From experience, If you inject in the ass you will feel pain for a couple of days. If you inject in the shoulders you will only feel pain that night and a little bit the next day but you can deal with it. AS FOR SLEEPING ON THE SHOULDER YOU INJECTED ON: I WOULD NOT RECOMMMEND IT BECAUSE IT HURTS LIKE HELL. I would probebly sleep on my other shoulder not on the shoulder that I injected on. JUST USE COMMON SENCE BUDDY.

B.F.S

BIGGER FASTER STRONGER!!