Litchi contains two "toxins": alpha-methylmethinepropylglycine (MCPG) and the amino acid hypoglycine A. They can inhibit the synthesis of glucose, thereby significantly lowering blood sugar and causing acute hypoglycemia. The disease, often referred to as "lychee disease," can be fatal. These two toxins mainly exist in the lychee core, and the content in the pulp is relatively low.