Generic wellbutrin has several manufacturers, and some people have real problems if the pharmacy switches suppliers. I had this problem a couple of years ago. My pdoc made note with my pharmacy for future reference not to use the manufacturer to fill my prescription. I have no problem with the one the use now, but that one switch messed me up literally for several months, even though I only took the one that caused the problem for about a week. The other thing your pdoc can do is note brand name necessary on your prescription. It will cost more, but you don't have to worry about manufacturer switches. I prefer the lower cost, so I've just learned to check the manufacturer name when I get a refill.