Indeed, it's entirely possible for people to take heroin at the weekends or similar, and put it down without problems, and I know several friends who do it irregularly without getting addicted - although only smoking, I've never heard of anyone injecting IV heroin who wasn't an addict...

Injections are apparently much more potent than smoking, so it makes sense that people already addicted prefer that to keep the required amount lower. For recreational uses, smoking would just be much more practical.

Indeed. The bio-availability from 'chasing the dragon' on tin-foil is something like 50% or even less, although in the UK at least powdered heroin is adulterated with things like caffeine (which causes heroin to vaporize at a lower temperature) to make smoking more effective. Obviously IV injecting gives 100% bio-availability, though.

I’d like to take the opportunity and thank you for posting here. It’s hard enough to find reports of people that are going through a withdrawal, so being able to engage in a discussion is a rare opportunity. I wish you all the best in that process.