Vidalista 80 mg treats erectile dysfunction, a medical condition in which the penis is unable to achieve a strong erection when a man is sexually aroused. The main ingredient in this medicine is tadalafil. This drug relaxes the blood vessels and helps increase blood flow to the muscles. It is advised to take this medicine one hour before planning to have sex to improve your sex life. The drug can also be used on an empty stomach. The effect of this medicine usually lasts for 3 to 4 hours.