Penis pills, not really. Dodgy drugs? Hell yeah.
Especially in the dodgier corners of Ye Olde Global Marketplace; various sorts of fakes, under-strength tablets, mislabeled or adulterated product, etc. are wildly common(often outnumbering the real thing). This both has a tendency to kill patients, since they don’t actually get the drugs prescribed, and encourage resistance among pathogens(since they often do get a trace dose of the right drug; but not an adequate one).
(Though, in defense of Viagra’s ‘Global Good’ cred, if anything can encourage people to stop killing every endangered animal with some dick-shaped structure and grinding it up for ‘traditional medicine’ that claims to restore vitality and let you get it up; it would be a relatively cheap, comparatively easy to synthesize, drug that actually does help you get it up.)