Regular Wellbutrin, which is not sustained or slow-release, and Wellbutrin SR
, the sustained/slow release type. Zyban and Wellbutrin SR
are the same drug with different names. The research regarding bupropion and smoking cessation is all based on studies which involve the SR variety. So anyone using Wellbutrin instead of Zyban should use Wellbutrin SR - not plain old Wellbutrin, which is released immediately.