Tadacip relaxes the penile blood vessels when a man is sexually stimulated. This allows blood flow into the male organ, resulting in an erection. The erection subsides after making love, just as it is supposed to in normal conditions. Please note that Tadacip is not a hormone or aphrodisiac, it works only when a man is sexually stimulated. Tadacip works by increasing blood flow to the male organ to help a man get and keep an erection.