The difference between levo-amino acids and dextro-amino acids lies in the different characteristics, different precautions, different properties, and so on. Different types can only work in different fields. 1. Different characteristics: mainly, the left spin amino acid can be directly and effectively metabolized to the heart, brain, fat, muscle and other tissues to produce ketone bodies and alanine. Dextro amino acid belongs to a kind of life molecule with fixed chemical composition. 2. Different precautions: the contraindications of levulinic acid include lactating women, asthma, malignant tumors, cardiovascular and cerebrovascular diseases, mental illness and so on. While the right amino acid belongs to the scientific field and there is no contraindication. 3. Different nature: levo-amino acid is an auxiliary treatment of disease drugs. The right amino acid is a chemical product synthesized by two different chemical molecules.