My boyfriend is 41 & I'm 31

We both have an amazing connection mentally and physically. But lately he started a new medication that will not allow him to "finish". I don't know what to do. I feel responsible but he says it's his medicine he's on. He always continues to get me off but I just feel bad about the entire thing. The medicine he's on is called adderall for ADHD. Anyone have any thoughts about this? What should I do? Thanks so much for input. No negative feedback please.