One of the most often used medications for males with severe erectile dysfunction is Vigora 100 (sildenafil citrate). The well-known salt sildenafil citrate, which was initially marketed as Pfizer’s Viagra, is found in Vigora 100. A phosphodiesterase (PDE-5) inhibitor is Vigora 100 Tablet. By relaxing the muscles in the penile blood vessels, it increases blood flow to the penis.