Avanafil
"As prescribed, I took 1/2 pill (100mg) of Stendra after a night of adult beverages, good food, and dancing.
Less than 30 min later, with her prompting, I was harder than ever and lasted 2 hrs. We're very happy.
No negative side effects. 
NOW, here's the good part.............
4 hours later, without taking any more Stendra, it was still working
4 hours after that, same thing. Poor wife was lethargic for the next 24 hrs. 
Thank you Stendra
ps- had tried Cialis and Viagra in the past with poor AND negative results."