Zhewitra 20 mg contains the active ingredient vardenafil, which belongs to a class of medications known as phosphodiesterase type 5 (PDE5) inhibitors. It is primarily used to treat erectile dysfunction (ED) in men. Vardenafil works by inhibiting the enzyme phosphodiesterase type 5, which leads to an increase in the levels of cyclic guanosine monophosphate (cGMP) in the corpus cavernosum of the penis. This results in relaxation of smooth muscles and dilation of blood vessels, leading to increased blood flow to the penis during sexual stimulation. As a result, men can achieve and maintain an erection suitable for sexual activity. Zhewitra 20 mg is typically taken orally, as needed, approximately 25 to 60 minutes before sexual activity. The onset of action may vary among individuals, but it is generally recommended to take the medication on an empty stomach for optimal absorption.