Cenforce D primarily addresses ED symptoms by enhancing blood flow to the penis. When a man experiences sexual stimulation, the arteries in the penis relax, allowing increased blood flow into the spongy tissues called the corpora cavernous. This increased blood flow results in a firm and lasting erection. The active ingredient, sildenafil citrate, helps to inhibit the enzyme that can constrict the blood vessels in the penis, allowing for improved blood flow.