Vidalista 20 How Long Does It Last? The active ingredient in the combination medicine Vidalista 20 is tadalafil. By interacting with blood vessels, the medicine’s ingredients relax them, improving blood flow to the penile region. This effect of the medication allows patients to control the ejaculation process and achieve a high-quality erection. Never take the medicine in greater quantities or more frequently than a doctor has prescribed. Drink a glass of water and swallow the tablet whole. This medicine should not be used in conjunction with any other topical medications or erectile dysfunction treatments.