The biggest cuase of decreased sexual function and impotence in middle-aged and older men is vascular-atheroclerosis of arteries supplying the penis or leaking of blood, needed to maintain an erection, into the veins too soon. Jiaogulan, like ginseng, is well known to lower serum cholesterol, triglyceride and LDL while increasing HDL. Clinical tests have shown Jiaogulan's ability to inhibit the aggregation of blood platelets (blood clots). Cholesterol build-up and platelet aggregation are two conditions than can severely hamper circulation. Dan Shen also helps by its action of improving the microcirculation throughout the internal organs of the body. In addition, Ginkgo biloba, being an artery and capillary dilator, assists in improving blood circulation.