Sildenafil
The active ingredient in Viagra, a medication used to treat erectile dysfunction by increasing blood flow to the penis.
Sildenafil belongs to a class of drugs called PDE5 inhibitors. It works by relaxing the blood vessels in the penis, allowing blood to flow into it during sexual arousal.
It is typically taken completely on an as-needed basis, about 30 to 60 minutes before sexual activity, and its effects generally last for up to 4 hours.
Because it is an older, off-patent drug, sildenafil is widely available as a highly affordable generic through telehealth platforms.