Cenforce 150 mg contains sildenafil citrate, a phosphodiesterase type 5 (PDE5) inhibitor. It helps increase blood flow to the penis by blocking the PDE5 enzyme, which relaxes the blood vessels. This action helps achieve and maintain an erection in response to sexual stimulation. Rare but serious side effects include priapism (a prolonged and painful erection), sudden vision loss, or sudden hearing loss. If you experience any of these symptoms, seek medical attention immediately.