Viagra helps stimulate erections by increasing levels of cGMP, which is also involved in blood clotting. Therefore, by increasing cGMP levels, Viagra could increase the risk of blood clots, according to the researchers. The FDA had previously warned of an increase in blood clots related to testosterone therapy in men with a condition called polycythemia. Polycythemia is a condition in which the body produces too many red blood cells, increasing the risk of blood clots forming.
His latest warning comes from reports of blood clots in men without polycythemia. Blood clots can prevent blood from flowing properly throughout your body and can cause you to have a heart attack, stroke, or other medical emergency. The advertisements for the male hormone imply that it may be just what a man needs to increase his energy, mood and sexual desire.