Vigora 100 mg is a medication used to treat erectile dysfunction (ED) in men. Its active ingredient is Sildenafil Citrate, which is the same ingredient found in Viagra. Sildenafil works by inhibiting the PDE5 enzyme, which leads to increased levels of cyclic guanosine monophosphate (cGMP). This results in relaxation of the blood vessels in the penis, enhancing blood flow and facilitating an erection in response to sexual stimulation.