I have not taken it, but I mentioned Tegretol to the P-doc as an idea, to replace Li and hoping for a weight neutral effect, and she told me that one can gain weight on Tegretol. And, Trileptal is related to Tegretol; either it is a derivative or a form of it, but it is related to it. So I would think that what holds true for Tegretol might also hold true for Trileptal.