OKay, here's a point. I want to know if previous drug use, such as stimulants like coke would interfere with it's efficacy. I have a friend whose GF is using it and it's been pretty ineffective. I figure it could either be that, or she didn't use benedryl prior to using the clen to reset her receptors, or that she drinks and is too undisciplined to get benefits. Anyway, I would expect something like clen (if a persons body weight ISN'T changing prior to using it) to cause a change if all other things are maintained and the clen is added. Any thoughts? But for my 3rd hand info, I have definitely seen/heard of someone using it without much positive effect, but wanted to include those potential reasons.