The Pharmaceuticals that you buy OTC in Mexico are the standard high quality and legit...in most cases. Same as if your a native Mexican citizen. Fraud of course is around, but like on the street the old motto is "Know your dealer". There's products from Germany, Europe, Asia(all over) and Mexico it's self. No doubt, they are cheaper though gringo's prices might be a bit higher. Depends on which outlet you go too.
I'm only familiar with TJ, Mexicali and Tecate, living in San Diego county most of my life.. High school and colleges jocks have been going across from the San Diego area for decades. As have lifters and BB'ers. Viagra be reason to go also.
A lot of American family's take their kids across for dental work, doctors and medical operations . A few American doctors there, but Mexico does have some very high quality medical doctors and medical personal. American's, more so now, are going into Mexico when some American's are pretty much living paycheck to paycheck. Even for gas and motor oil in border states
Really going to have to watch you back when crossing over. Not like it use to be. If first time visit to a border town might want to go with someone who has been there before. Never ever go down side streets. TJ is a major cartel center and has been for years. Migrants are overflowing TJ so problems do arise from time to time.
Use to have a couple of fine gyms near downtown TJ. Don't know if their still there or not. Have mot heard much about them for a while.