Is the cb-1 weight gain supplement bad for your or can cause death?

Not known for sure: Nobody really knows. The supplement is not a medication approved by the FDA. Such products are probably not tested for interactions and side effects like real medicines are. So, that means nobody really knows what side effects there are (nor what benefits are real, if any). If a CB-1 user hears of some interaction or thinks he is getting a side effect, he can visit his primary care doctor.