Generics are all different

[suzi11]

Ive learned that generics are not exacly the same as the brand . They are allowed to have different fillers etc. Up to 20 %  diierence from main ingredients. I take generic adderall IR. My pharmacy usually gives me generic by corepharma. Just once had (or gave it to me cause of my complaints) generic by another manufacturer where I didnt have all the side affects and worked much better. I found out its more exspensive so pharmacy doesnt have it often. Anybody can help with what are my rights to get the generic that works?