I live in Tijuana and it's actually not super dangerous unless you go to a bad neighborhood. Sure, relatively statistically speaking, there is a higher chance of something bad happening. But it is still a very tiny chance if you stay within nice neighborhoods and are just trying to buy medication. By the way, unfortunately the only part that of Tijuana that a lot of Americans see is the one designated for maximum debauchery and is one of the worst neighborhoods.

The pharmacies right by the border are fine, but if you want a nicer area, walk across the PedWest crossing and stand in the Uber waiting area for an Uber to go to Playas. Then you can go somewhere like Farmacias Roma or Farmacias del Ahorro or a bunch of other nice stores with people wearing lab coats. You could also just go to Walmart for medication if you want but recently they seem to be missing basic things I needed so they probably aren't the best.