Sildenafil is a component in Penegra 25 MG Tablet. It is better known as the blue pill. Men with erectile dysfunction (ED) may gain greatly from this drug. Men who suffer to achieve and/or maintain an erection strong enough for sexual activity are said to have erectile dysfunction. This occurs as an outcome of decreased circulation caused by physical injuries, specific medical disorders, or certain mental illnesses like anxiety, stress, depression, etc.