Name: Huanyangjian Character: This product has been highly purified into white powder crystal which can dissolve in water and ethanol but can't dissolve in fat. It is smelless and bitter with the purity of above 99.95%.The product should be kept in dark and dry place. Function: The acting principle of this product: NANC neuron and carbon monoxide enzyme of blood vessel endodermis cells catalyze the composition of carbon monoxide from L-Arginine. Carbon monoxide stimulates the composition of guanosine which can lead to the relaxation of smooth muscle of penis sponge and penis arteriole. The penis will have an erection when there is blood pouring into penis sponge. Thus, this product belongs to 5 types Vinpocetine (sildenafil). Effects: This product is re-composed by sildenafil which belongs to the derivatives of sildenafil. And its changeable forms LG-MS, HPLC have been tested by advanced facility and have passed international intellectual property protection policy. It doesn't belong to the protection scope but also doesn't in the forbidden scope of government. Harmful reaction: Headache, red face, nasal congestion, abnormal eyesight (barrier of distinguishing color in a short time).