{Mods - I don’t use heroin, nor intend to. This isn’t seeking medical advise. It’s a question about human body physiology}
All I know about shooting heroin has been learned from movies and TV, in otherwards no real life knowledge. Having said that, it appears the optimal way is to wrap an elastic band around your arm, slap your forearm a few times to get a vein to rise the inject into that vein. Makes sense.
But another trope I see often (did again last night Behind Her Eyes) is to shoot between your toes so as to hide the track or injection sites. But there seems to be a world of difference between that as opposed to injecting it straight into a vein.
If one were to just randomly inject heroin into the body somewhere, is it still effective? And if so, why go through all of the trouble to find a vein?