cGMP is a molecule that helps relax blood vessels, increasing blood flow, which is essential for an erection. PDE5 is an enzyme that breaks down cGMP. PDE5 inhibitors, like sildenafil, prevent this breakdown, allowing cGMP to last longer and enhancing erection quality. Regarding lifestyle, regular exercise, a balanced diet, quitting smoking, and reducing alcohol can all support healthy blood flow and potentially boost cGMP levels naturally.