Vigora 100 is a drug that is mainly used to treat erectile dysfunction (ED) in men. It is a member of the class of medications known as phosphodiesterase type 5 (PDE5) inhibitors. Vigora's active ingredient, sildenafil, helps men get and keep an erection by increasing blood flow to the penis during sexual stimulation.

The arteries in the penis relax and widen when a man is sexually aroused, allowing more blood to flow into the erectile tissue and resulting in an erection. In men with ED, however, this process is disrupted for a variety of reasons, including psychological problems, lifestyle factors, or underlying medical conditions. Sildenafil helps to counteract this by inhibiting the enzyme PDE5, which normally breaks down a substance called cyclic guanosine monophosphate (cGMP), which relaxes the smooth muscles in the penis and dilates the blood vessels, allowing an erection and facilitating increased blood flow.