Viagra

Viagra, or sildenafil, is a PDE5 inhibitor medication used to treat erectile dysfunction (ED) in adult males. Both brand name and generic Viagra comes in 25mg, 50mg, and 100mg strengths, and is usually prescribed to be taken 4 hours to 30 minutes before sexual activity. If you've been prescribed Viagra or sildenafil, it's important to know the side effects, interactions, and directions before taking it the first time. To learn more about Viagra, read our articles below.