I'm confused as to what you are speaking about. Mike at 1fast doesnt carry clen (least I remember him saying he would never carry research chems) while custom does. Do you know what clen is/does? If not completely, stay away from it. It is very potent and strong. You might be confusing clenbutrix (or some other name similar to clenbuterol) on Mike's site. Let me assure you they are very different compounds; the companies making those other products chose a name similar to clenbuterol because they want to show their product's strength and think it worthy of a name similar to clen. None of these products come close to clen.