Suhagra 50 mg contains 50 milligrams of sildenafil citrate, which is the active ingredient responsible for its therapeutic effects. Sildenafil citrate is a phosphodiesterase type 5 (PDE5) inhibitor, which works by increasing blood flow to the penis during sexual stimulation. This helps men achieve and maintain an erection suitable for sexual activity. Sildenafil citrate does not directly cause erections but enhances the natural response to sexual stimulation.