Cenforce D is a combination of two active ingredients: Sildenafil and Dapoxetine. Sildenafil is a phosphodiesterase type 5 (PDE5) inhibitor, which works by relaxing the blood vessels in the penis, allowing for increased blood flow and facilitating an erection. Dapoxetine, on the other hand, is a selective serotonin reuptake inhibitor (SSRI), designed to delay ejaculation and help men with premature ejaculation.