Any reason these don't mix, or any reason why they would cancel out each others effects. Since some resent talk here on the boards about 5-htp, I decided to include it into my daily routine for the next few weeks, not for recreational purposes, but the actual usage. So I don't want to cancel it out. but I'm on day 1 of a month break, and want to get clean asap, so I'm using niacin as well. So I don't want to cancel any effects, and since both have appetite usages, I'm concerned if there will be any issues. Anyone know?