An enzyme called PDE5 is inhibited by the ED medication vidalista 80 (generic Viagra®), increasing blood flow to the penis. This makes it easier to get a harder erection.

It acts in as little as 30 to 60 minutes when taken orally as a tablet, and it remains in your body for 4 to 6 hours. An erection will only happen when you feel aroused, so don’t worry—sildenafil doesn’t cause arousal.