> As a side note, this letter is exactly why I think a regulatory agency like the FDA is absolutely necessary. This stuff can kill people and it is impossible for the average person to protect themselves.

The mislabeling is certainly a problem, but really these drugs (sildenafil and tadalafil) should be over-the-counter and cheaply available on Amazon as generics. That they are not is a failure of the same FDA. They have a great safety profile and limited contraindications, comparable to many other OTC drugs.