I’d be surprised if the buyers were expecting any different.

With the amount of mislabelled product out there in circulation (and presumably a general lack of harm), does it still make sense to require a prescription?

I'm personally pretty torn on that. On the one hand I agree with you, especially from a harm-reduction perspective (e.g. people who are on blood pressure medication ordering "natural" Viagra because Viagra's contra-indicated with the medication they're on, not realizing that they're getting something that could cause a very bad situation). On the other hand, requiring a prescription does mean that a physician can ask that question ("are you on blood pressure medication?") and counsel the patient to look at different options instead.

I mean, even though 50% of these are intentional overdoses... the other 50% probably didn't know they were doing something that was going to destroy their liver: https://www.ncbi.nlm.nih.gov/books/NBK441917/

It’s pretty much just an interaction with “nitrates” which are typically taken by people with pretty serious cardiac issues, and usually educated re: the side effects if taken with viagra or similar compounds (cuz you never know if someone has Viagra in their drawer from another pharmacy or years ago or “natural” Viagra from another source).

The interaction with other blood pressure meds appears additive rather than synergistic and Viagra alone only minimally reduced blood pressure. The cough and cold aisle or a cafe presents more dangers.

https://pubmed.ncbi.nlm.nih.gov/10078539/

At least over the counter Viagra would be properly labelled about these things.