Sildenafil (Viagra)

Sildenafil (commonly known by the brand name Viagra) is a prescription oral medication used to treat erectile dysfunction by increasing blood flow to the penis during sexual stimulation. 

How It Works

• PDE5 Inhibition: It blocks the phosphodiesterase type-5 (PDE5) enzyme, allowing blood vessels in the penis to relax and fill with blood.

• Requires Arousal: It does not cause an automatic erection; physical or mental sexual stimulation is required for the drug to work.

• Timing: It typically starts working within 30 minutes and remains effective for up to 4 hours