Sildenafil Citrate the citrate salt of sildenafil, is an oral medication used to treat male erectile dysfunction. Sildenafil Citrate acts by inhibiting an enzyme, cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5, that regulates blood flow in the penis. Sildenafil Citrate is the most popular and well known medication used for the prime treatment for erectile dysfunction, it helps men to achieve and maintain erections