Zenegra 50 mg belongs to a class of medications called PDE5 inhibitors, which block the phosphodiesterase type 5 (PDE5) enzyme. PDE5 normally breaks down a substance called cyclic GMP that helps relax blood vessels in the penis. By inhibiting PDE5, Sildenafil increases the concentration of cyclic GMP, allowing for more blood flow to the penis when sexually stimulated.
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