Vialis is a medication that is prescribed by doctors for a variety of purposes. It works by relaxing muscles and increasing blood flow to certain parts of the body. One of the most common uses of Vialis is for the treatment of erectile dysfunction in men and symptoms of an enlarged prostate. Unlike other drugs used for erectile dysfunction, such as Viagra, Vialis has a longer lasting effect, with the ability to produce erections for up to 36-48 hours from a single dose, while Viagra is limited to 4-6 hours. Due to its long half-life and even longer active life, Vialis is commonly referred to as “The Weekend Pill”.