I’ve insufflated a tenth of a 200mg IR tablet of Diaphin once, which is a Swiss pharmaceutical preparation of diamorphine. It felt very good ngl, hands down the best opioid I’ve tried but I haven’t craved for it or thought about it much, eversince.
For me, opioids are highly side-effect rich drugs which makes them pretty unattractive to me. Physical side-effects like itching and nausea while on it, constipation, rebound nausea and circulation problems for two days afterwards (even after single use), and psychological rebound effects like agitation and depression, also for solid two days.
I can still see why some people would throw their life away for this stuff though, because it’s very good at dissolving all your worries and problems while seemingly increasing the love for what you have and who you are. It’s the perfect anti-depressant in a sense because it’s manipulating you to think that your life is absolutely amazing, as long as you’re on it. Pretty scary to think about when you’ve tried it, but I still wouldn’t consider it to be much more addictive than morphine, oxycodone and the likes. It’s more euphoric for sure, but if you’ve tried stronger opioids without any issues before I don’t think this will make for a huge difference.
I urge you to be very cautious though and to really think this through. Once you try it you obviously can’t untry it and you will remember this feeling for a very long time. If you have had addiction problems or addictive tendencies in the past, or you have a "thing" for opioids, or depressants in general, I advise against trying it. Curiousity got the best of me too, and it luckily didn’t lead to any issues but it isn’t like that for everyone.
Besides, international Heroin quality is at an all-time low, so make sure what you have is actually Heroin. I suggest sending some in for lab-testing or at least buy a set of reagents to test for the presence of fentanyl. Start with a very low-dose and don’t redose too early. Stay safe!