As someone suffering a rotten spine, with all the back, muscle and nerve pain, I implore you, get him to try something else. I tried 7OH and it has its place - I agree 100% with ThemWitches. But the withdrawal would take out superman. You don't want anything to do with the withdrawal. The mental shit will kill him if the physical doesn't. Please research how sick people get before he takes it, because it's really bad. I needed actual spiritual help (religious stuff) to get me through it. As a long time opiate user, this was the worst it's been. I can't knowingly see someone who's never taken it, and not warn them about the withdrawal. It's the big bad wolf man.
After finally getting the 7OH out of my system I tried "Kratom Extract" tablets. Dissolvable. They work for pain. No high though, but if he has legit pain there should be no complaints. Its expensive. Opia has "Kratom Extract" and "Mitragynine Extract" and "Mitragynine" tablets. They're all the same thing just different names. I think its Opia staying ahead of the naming game. Good luck!