that 'heroin' used to be sold on the streeet in 00's or 90's doesn't exist anymore, i talk about acetylated with certain reagents morphine. now technically all heroin one sees in drug market scene is a mixture of additives with fentanyl. things with H turned like this because it's much profitable for vendor to substitute import of already dilluted and due to multiple complicated steps in drug production to terminal usr expensive 'afghan' heroin from third world with local production of synthetic opiate analogs i.e fentanyl, that's it's easier to sellout when all production chains located inside of one country or at least somewhere nearby. black tar heroine is only heroin left on the market sold as heroin bc there's no sense in faking its structure,color and consistency to sell it as pure heroin without fent. so my theory is that technically when one buy (white) heroin from darknet marketplace. as example, and investigated item review,s and is sure in some decency of the vendor, one is getting fentanyl/additive mixture which is certainly lethal if inject several gramms at once. problem is jail in case of handling more than allowed by law, though as far as i remember H used to be sold in so callled checks(0.3g of powder), buying one check per week and accumulate them shouldnt be problem since police certainly wouldnt be interested in some junkie who buy their fix once per week. injecting is not that hard if veins are visible, and cooking H before injection is quite basic, just needed to mix several gms in a spoon with some water added and heat with lighter untill powder is dissolved then dip in the solution a removed cigarrete filter, then insert needle in the middle of swollen filter and put in vein and inject, but there's no much difference if inject it in under skin instead, like insulin users do. opiates easily pass blood-brain barrier, you can even make opiate solution enemas or rub it in gums tho intramuscular or intravenous injections proven to be the most effective