Viapro is used to help achieve and maintain an erection in men.
Part of the physiological process of erection involves the release of nitric oxide (NO) in the corpus cavernosum.
This then activates the enzyme guanylate cyclase which results in increased levels of cyclic guanosine monophosphate (cGMP), leading to smooth muscle relaxation in the corpus cavernosum, resulting in increased inflow of blood and an erection.