No, veterinary grade isn't that bad. In fact it is often made in the same facilities and using the same standards as those used in the production of human grade medication. Oftentimes the only thing different is the label. Having once been a vet tech, and also a frequent visitor of mexican veterinary pharmacies, I've used
alot of veterinary grade medications.
The reference I made to "non-veterinary grade" actually refers to a deal I made with myself years ago. In this "deal" I told myself that I could still IV drugs if I wanted to,
but only on the condition that what I was injecting was in new, unexpired, non-veterinary grade, ampule or vial, made by a respectable manufacturer (i.e., not produced by some random company in Tunisia, etc). This "deal" with myself (a contract of sorts) essentially ensured that I would never be able to IV anything ever again given the rarity of ampules/vials of this nature. That's why I mentioned that I'd possibly consider it.
As a former ultra heavy-use drug addict, I don't believe in the concept of complete abstinence. I feel like those who subscribe to the idea of abstinence are the ones who suffer extremely severe relapses, because when they do use drugs again (while under the notion that total abstinence is needed), they go balls out since in their mind they've already relapsed and since they've failed by using a little bit of something, they have totally failled, and now might as well go hard and heavy since they are now "off the wagon". This is why, in part, the failure rate for rehabs and etc is so high.
So yeah, even though I haven't IV'd anything in over a decade, if, for example, if someone handed me a vial of human grade, non-expired ampule of numorphan (brand name oxymorphone) I would IV it right now.
Now, if somehow a few crates containing thousands of these came into my possession, I would need to renegotiate the "deal" to revise the terms and conditions since I don't ever want the kind of habit I used to have. Fortunately, I'll never find myself in such a condrum.