refers to promoting the production or supplement of blood and energy and other substances in the human body through the action of drugs.

Deer fetus is a kind of Chinese herbal medicine, which is sweet in nature and has the main function of enriching blood and replenishing essence, and is suitable for symptoms such as kidney deficiency and essence deficiency, weakness, and soreness of waist and legs. Among them, "enriching blood and replenishing essence" is a common concept in traditional Chinese medicine, which promotes the generation or supplement of blood and energy in human body through the action of drugs, so as to achieve the effect of nourishing the body. Deer fetus also has the same principle of action.

"Jing Xue" in traditional Chinese medicine refers to Yin and Yang qi and blood in human body. Among them, sperm refers to male and female germ cells, which exist in the kidney, so they are called "kidney essence" and "heavenly essence"; Blood refers to the liquid tissue with changed chemical composition, which is transformed from the absorption of nutrients by the spleen and stomach, and is responsible for supplying all kinds of nutrients and oxygen needed by the body, and at the same time expelling metabolites from the body. Therefore, "enriching blood and replenishing essence" in traditional Chinese medicine is not simply to supplement blood and energy, but to improve human function by regulating the balance of yin and yang and qi and blood, so as to increase physical strength and prevent diseases.