Jesus i'd forgot id even tried this one until reading this thread, can't have been good enough to make an impression then
That sums up my feelings about this substance. I tried oral (up to 120mg), nasal (30mg), sublingual (60mg) and smoked (15mg increments), and none of those ROAs brought anything definitively tangible. With oral it was a case of "yeah, I think I feel a bit of something now... maybe. Actually, I feel a bit queasy... maybe this is gonna go somewhere". But it didn't eventuate to anything more than mild nausea which hung around for a few hours. There was pretty much nothing in the experiences comparable to other opiates I've tried. I did have a good sleep that night, but it could have been a coincidence. It wasn't like that opiate sleep where you are kind of half awake most of the night and just enjoying every minute of lying there in your comfortable bed.
I have a moderate opiate tolerance, but not so high that I can't still enjoy a bit of codeine (usually aim for 500-700mg with a CWE) or o-desmethyltramadol (200mg oral is nice for me) because they have some of the qualities of opiates that I recognise and love: some physical pain relief, bit of a mood lift, relaxation of mind and body.
AH7921, on the other hand, really didn't seem to have any of those qualities. It's the least interesting opiate (opioid) I've tried. Perhaps I got a dud batch, or simply the secret of unlocking its potential (if it has any) has yet to be discovered.
I'd also be interested to hear more from people who have IV'd it...