I have been on the name brand of Protonix since 2000 and it has worked great. My problem started when the generic became available and my insurance co would no longer cover the Brand name. The generic medication didn't work at all. I thought it was me, that I became resistant to it. But after talking to the Pfizer nurse (their US Drug Safety Unit) I was told there are bad generic versions of Protonix on the market. I was able to get my insurance company to cover the brand name up until last September 2016. Now they refuse to cover it. There are approximately 17 different generic manufacturers I found online. Has anybody had a generic version of Protonix that worked as well as the name brand one.The manufacturer name should be somewhere on your medication bottle. If you can't find it on your bottle your pharmacist would be able to tell you the name. It may save me from pain and suffering and a lot of trial and error randomly trying each manufacturer until I find one that works.