Cenforce is prescribed to treat erectile dysfunction (ED) and impotence. Sildenafil is the active component in Cenforce. It relaxes muscles and blood vessels in the penis for greater blood flow, allowing a man to develop an erection.Cenforce 100mg contains sildenafil citrate, the same active ingredient found in Viagra. Sildenafil citrate is a phosphodiesterase type 5 (PDE5) inhibitor that helps men achieve and maintain an erection by increasing blood flow to the penis during sexual stimulation.