Ugh Topamax. I was on Topamax for a while when I was 17. I was in this weird study where they were trying a bunch of meds to see their effectiveness to treat childhood obesity. I didn't lose a significant amount of weight on Topamax alone. I hated Topamax and in hindsight, I think it was because I was blaming the drug for being depressed because I didn't want to admit that it was much more serious than a drug causing my issues. So I can't really talk about Topamax for migraines, but I can tell you not to expect to drop more than 5 to 10lbs