Essentially “V” inhibits the enzyme responsible for the constriction of the venous circulatory system. Basically it allows the veins to dilate, delivering blood to extremities, while to a smaller degree causing the arteries to constrict slightly, keeping the blood there.
Another effect this has, in addition to enhanced erectile function, is a lowering in blood pressure. It should be mentioned that “V” should not be used on a rat that is currently being administered nitrates for research purposes. (ie: nitro glycerin)
“V” is the flagship ED research chemical. It started it all, is powerful and fast acting, and in very high demand for research purposes.
Refs:
*Kloner RA (2005). "Pharmacology and drug interaction effects of the phosphodiesterase 5 inhibitors: focus on alpha-blocker interactions". Am J Cardiol 96 (12B): 42M–46M. doi:10.1016/j.amjcard.2005.07.011. PMID 16387566
*Pfizer, Inc. (June 6, 2005). "FDA Approves Pfizer's Revatio as Treatment for Pulmonary Arterial Hypertension". 2005 News Releases. Pfizer. Retrieved December 27, 2005
*Vardi M, Nini A (2007). Vardi, Moshe. ed. "Phosphodiesterase inhibitors for erectile dysfunction in patients with diabetes mellitus". Cochrane Database Syst Rev (1): CD002187. doi:10.1002/14651858.CD002187.pub3. PMID 17253475