Do they have negative stereotypes? Does one consider stereotypes when deciding whether to take a drug? I've never thought about the social aspect of any prescription I've gotten.
The idea that you'd "need" to take Viagra or Cialis is an assault on many men's sense of masculinity and virility.
When you are old and have to actually use these medications all you will be thinking about is how much it must have sucked before they were invented.
In a world absent stigma, perhaps these drugs would simply be seen as performance enhancing to the extent 21 year olds with perfectly functional circulatory systems would take them so they could go for a round 2 and round 3 more quickly.