L-carnitine, also known as L-carnitine, vitamin BT, chemical formula is C7H15NO3, chemical name is (R)-3-carboxy-2-hydroxy-N,N,N-trimethylpropionium hydroxide inner salt . It is a kind of amino acid that promotes the conversion of fat into energy, pure product is white crystal or white transparent fine powder, very soluble in water, ethanol, methanol, slightly soluble in acetone, insoluble in ether, benzene, trichloromethane, ethyl acetate. L-carnitine is very easy to absorb moisture, has good water solubility and water absorption, and can withstand high temperature above 200℃. It has no toxic side effects on human body, red meat is the main source of L-carnitine, and human body can synthesize it by itself to meet the physiological needs. It is not a real vitamin, but a vitamin-like substance. It has many physiological functions such as fat oxidation decomposition, weight loss, anti-fatigue, etc. It is widely used as a food additive for infant food, weight loss food, athletes' food, nutritional supplements for the middle-aged and elderly, nutritional fortification for vegetarians and animal feed additives, etc.