Vidalista 40 contains the active substance Tadalafil 40 mg. Tadalafil relaxes muscles of the blood vessels and enhances blood flow to particular areas of the body. This increase in the blood helps a men to get a hard erection for long hour of time up to 36 hours by taking it before 30-45 minutes of planning to have s*x. Before buying you can also know its review, side-effects, how its work etc., from medypharmacy.