The main active component of Eriacta 100 mg, Sildenafil Citrate is a member of the class of medications known as PDE5 Inhibitors. PDE5 inhibitors are a class of drugs that regulate and hasten the breakdown of the cGMP enzyme. It in turn causes the blood flow in the penis to rise. As a result, it provides both you and your partner with long-lasting sexual stimulation by boosting circulation in the penis.