I was also on Teva clonazepam for 13 years with no issues. A few months ago I switched pharmacies and started getting Actavis which I have been experiencing weight gain, headaches, extreme drowsiness with the same dose as the Teva, 1 mg 3x per day. I am very sensitive to medications and have racked my brain on the weight gain issue thinking it's hormonal, etc. but I really think it is the medication. I gained 30lbs in 2 months on Zoloft when the dr. told me "no one gains weight on Zoloft." I contacted the pharmacy and requested they exchange the Actavis for the Teva and hopefully I will get back to normal. Anyone else have this problem?