I think it took over a month for me and I was at 200 mg. I had a lot of ups and downs and worsening depression but in the end I felt better than I ever have. This was 4 years ago though and the effects have not lasted. My doc has tried me on different meds and dosages, though I have still been on Lamictal the whole time. I don't know if it wears off with time but when it first kicked in it was really amazing. It was the first drug that had ever worked for me. I hope you feel better soon.