Everything i could find points to a diet pill, however, I couldnt find one so there isnt any confirmation, Sorry!
what shape and size is it. is GMP-12 situated just like that, or one on top of the other, or part one one side of the pill part on the other side. details.....
Yeah. The rxlist pill identifier doesn't have it in the database, which likely means it is not an FDA approved medication. So, I tried it on google, and like BottleFED found, the only thing related to it are non-FDA-regulated diet pills. So, I am doubtful there is any opioid potential in that pill.
Another very real possibility!! I never even considered 'the obvious' haha. GMP might just be the acronym for a candy company.