Well codeine phosphate is a [P] medicine in the UK but that won't nearly cover the oxycodone I take. I don't abuse them - I take one tablet every 8 hours (Oxycontin lasting 12 hours is a LIE) and that's it.
I've always have at least 28 days in hand - hence my saying I had unopened boxes plural.
But I admit, I used to know people who sold methadone. In this town it seems like supervised consumption has ended that. I've only ever taken prescription medicines. So while H is about, it's not appropriate.
I even wondered about asking if methadone might be a better option than OC but there are issues. When given for pain, it comes as small tablets. The problem is, so few people take it for pain, there have been problems with the supply of tablets.
I don't know what UK law says about kratom. It's a grey area.