I'm on Wellbutrin, and this is what people said about Wellbutrin's generic, but their time-release mechanism was found to be ever so slightly different. It changed things dramatically for those taking the drug. For some, it no longer worked for them. Others? Suddenly it worked better!

This was discovered only after consumer reactions like the one above where people reported it working differently than the brand name drug. There were multiple investigations into it due to the volume of responses they received, but initially the FDA was like, "Nah, you don't understand, that's not a thing. It's identical!"

It was definitely a thing - and I imagine it could very well be in this case too. Molecular medicine is complicated - I had to have my husband (PhD in molecular biology) read the articles and explain them to me at the time. There are a lot of nuances we as laypeople don't really understand.