Sildenafil is an active and most widely known prescription ingredient approved by the FDA for ED (erectile dysfunction). It was familiarized by the brand name of Viagra and is now available in generic form. Nickname of the Sildenafil Citrate is ''The Blue Pill'' or ''The Little Blue Pill'', it was the first phosphodiesterase 5 inhibitor approved to treat Erectile Dysfunction. ED is a common sexual problem for men and its frequency increments with age.
