I have had a similar experience as many others who have written. I took Wellbutrin (with no side effects) for years, until my insurance company made me change to Budeprion in June 2007. Almost immediately I started feeling dizzy and had terrible nausea. My MD kept saying it was not the Budeprion, but that was the only new medication I was taking. Over the next year, I had a colonoscopy, endoscopy, CAT scans, MRI's, blood tests and breath tests to find out what was wrong. Everything came back negative, and my MD diagnosed me with Irritable bowel syndrome. On my own I decided to cut back the Budprion from 300 mg to 150mg, and I did feel a little better for awhile, but then the nausea came back worse than before, and I definitely noticed that it started about 4 hours after taking Budeprion. I decided to skip it entirely for a day or two, and each time I did, I had no dizziness or nausea. My MD can say whatever she wants, but I know the medication is what made me sick. I don't know if my insurance company will let me go back to Wellbutrin, but I do know I will never take Budeprion again.