Actually regarding heroin users they tend to be very non-sterile and clueless about it. I saw a documentary about a bunch of hardcore addicts, forget about reusing needles not only they reuse the same needles a million times they share needles with each other, i mean if your a couple i guess thats okay... u would think thats the worst of it, hell no the dude in the documentary washed his syringe in a mcdonalds toilet THE TOILET!!!! Then the need was all bent up fell to some lobby floor many times. They use bottled water to inject without sterilizing the area, the spoon or anything really. Get this this couple made around 1000-1500 a week by stealing, whoring, and family money donations. They managed to spend it all I mean dame they are smart enough to hustle that kind of money out of nothing yet not smart enough to use proper injection techniques? When i saw that I was like naw they just picked the craziest people.
Then I met some dude who is a hardcore heroin addict he doesn't seem that careless but (he is a liar and a hustler and the most stupid criminal I ever met) he does reuse the same needle a million times which i suspect would lead to blood decaying inside the needle and bacteria forming inside the syringe. He again just used bottled water not even distilled no disinfectant on skin straight into vein and remember you have no idea who handled the product and how, thats just disturbing to me.