Penegra 50 mg belongs to a class of medications called phosphodiesterase type 5 inhibitors (PDE5 inhibitors). When a man is sexually aroused, nitric oxide is released in the penis, leading to the production of cyclic GMP (cGMP), which helps relax the smooth muscles of the blood vessels in the penis, allowing more blood to flow in. PDE5 is an enzyme that can break down cGMP, which reduces blood flow to the penis. Penegra 50 mg inhibits PDE5, ensuring that cGMP remains active longer and allowing for improved and prolonged blood flow to the penis, facilitating an erection.