You can't get human pharmaceutical grade Dianabol over the counter in Mexico, but you could buy it from vet stores... my experience is: even in vet stores here in mexico Dianabols (and other "not-meant-for-human" anabolicos) are not over the counter, i have to talk to the manager and she'll take me to her office and ask me what do i want, then she will write it down and have it all ready for me about 5 days later...
(Dianabol is not meat for human use in Mexico as far as i know)