You shouldn’t do any drugs but heroin and crack are especially nasty I think- don’t know what kind of dealers you’d obtain them from? The ones I know of in both my own area and my uni city (I mean know of, not necessarily for personal use
have coke, mdma, weed, pills but I’ve never come across ones that offer crack or heroin. I know heroin powder isn’t the same as injecting it but never even seen that
Opiates like heroin don’t really appeal to me anyway, surely they make you feel high but sleepy and a little bit sick