Vidalista 80 contains tadalafil 80 mg. Tadalafil is not considered a water-soluble drug; it has low water solubility and is classified as a poorly water-soluble compound. This means: It does not simply dissolve in water like salt or sugar. The tablet is designed to dissolve and release tadalafil inside the body after swallowing. Crushing, dissolving, or altering the tablet is not recommended unless a healthcare professional or the product instructions specifically allow it. Also note that Vidalista 80 is a very high dose of tadalafil compared with commonly used tadalafil doses for ED (often up to 20 mg when taken as needed). Higher doses may increase the risk of side effects such as headache, dizziness, low blood pressure, muscle aches, and back pain. Do not use tadalafil with nitrate medicines (such as nitroglycerin for chest pain) because the combination can cause a dangerous drop in blood pressure.