Tadarise 20 mg contains Tadalafil which works by improving the flow of blood which flows within the penis of a person at the time of sex. This drug works as a PDE-5 inhibitor which stabilizes the extent of the cGMP enzyme. This further prevents the formation of the cGMP enzyme which causes a rise within the level of gas. gas helps in improving the flow of blood which successively enables a person to possess a firm erection at the time of intercourse.