Sexual Enhancement Ingredients--D (Xin yangjian) Characteristics: light yellow crystal powder in high purity; slight soluble in water and ethanol; melt in lipids; odorless Purity: 99.5% Pharmaceutical theory: This ingredients belongs to phosphodiesterase type 5 of this kind of inhibitor. When sexuelle erregung, neurone of NANC and nitrogen oxide inendothelial cells synthase and catalyse L-arginine to synthetize nitrogen oxide, which activate guanosine to synthesis increase, then lead cavernous body of penis smooth muscle and artery of penis into relaxation, blood into penis sponge sinus, make penis erect. Indication: sexual function decline; non-organic sexual disorder, ED patients