Well the fentanyl that comes from Mexico or China that is being used to lace h or used in counterfeit pills is basically ugl, I doubt there’s a lot of quality control that goes into it lol. Actually from what I understand fentanyl is cheaper than heroin, so it makes a good cut to bring up the strength of crappy low quality h, unfortunately it’s dosed in micrograms usually, except for a 1.6mg lollipop and the patches (used to smoke them lol) so it’s quite easy for drug dealers to add too much. Actually saw on drugsinc the dealer said he purposely added a hefty dose to a bag of h so that someone would OD to make people think his shit was fire. It’s mlre potent, more sedating than morphine or h but like I said the high isn’t as potent. It has a better high than Xanax imo, but it’s exceedingly dangerous to add it to counterfeit pills. Honestly the gave me a fat shot for before my surgery, like a lot higher than they normally give out but it didn’t really make me want to use afterwards.