To understand how Sildenafil works, we first need to understand what causes Erectile Dysfunction. Erectile Dysfunction occurs when the blood flow to the penis is hampered.
Sildenafil is an oral therapy for Erectile Dysfunction. In medical terms, it is an inhibitor of cGMP Phosphodiesterase (enzymes that maintain the signal pathways for muscle contraction and relaxation).
Sildenafil inhibits the Phosphodiesterase that helps contract the muscles and increases the blood flow in the penis muscles to achieve an erection.
Remember, you should be sexually aroused if you want to achieve an erection with this medicine. A proper dosage system is required to get the necessary erection. It is also important to note that while Sildenafil can help you attain an erection, it cannot prolong an erection. In the case of women, it improves the blood flow to their genitals, thus improving sex drive. (Langtry, H.D., and Markham, A., 1999)