Tadalafil is the main and active ingredient of the Tadarise 2.5 pill, a drug for the treatment of penile erection in men. It occurs when the penis does not receive enough blood to remain hard and erect for the intended duration of sexual activity. This medicine is recommended only for men aged 18 or older. This drug works best on an empty stomach, so avoid eating a fatty meal before you intend to have sex. As the effect of this medicine lasts for a long time, this medicine should be used as per the advice of your doctor. Using this medicine improves your sex life.