L-leucine (L-leucine), also known as leucine, is α-amino-γ-methylpentanoic acid, α-aminoisocaproic acid, and its molecular formula is C6H13O2N.Proust was first isolated from cheese in 1819, and later Braconnot was crystallized from the acid hydrolyzate of muscle and wool, and named leucine.

Physical and Chemical Properties:

1. White crystal or crystalline powder; odorless, slightly bitter taste.

2. Soluble in formic acid, slightly soluble in water, very slightly soluble in ethanol or ether

Efficacy ：

1.L-Leucine can be used as a nutritional supplement and flavor enhancer. Amino acid infusions and comprehensive amino acid preparations, hypoglycemic agents, and plant growth promoters can be prepared.

2. Leucine's actions include working with isoleucine and valine to repair muscle, control blood sugar, and provide energy to body tissues. It also increases growth hormone production and helps burn visceral fat, which, because it's located inside the body, can't be effectively affected by diet and exercise alone.

3. Leucine, isoleucine, and valine are branched-chain amino acids that help promote muscle recovery after training. Among them, leucine is the most effective branched-chain amino acid, which can effectively prevent muscle loss because it can be decomposed and converted into glucose faster. Increased glucose prevents damage to muscle tissue, so it's especially good for bodybuilders. Leucine also promotes the healing of bone, skin, and damaged muscle tissue, and doctors often recommend leucine supplements for patients after surgery.

4.Since it is easily converted to glucose, leucine helps regulate blood sugar levels. People with leucine deficiency can experience hypoglycemia-like symptoms such as headaches, dizziness, fatigue, depression, confusion, and irritability

5. The best food sources of leucine include brown rice, beans, meats, nuts, soy flour, and whole grains. Since it is an essential amino acid, this means that the body cannot produce it itself and can only be obtained through diet. People who engage in high-intensity physical activity and a low-protein diet should consider taking a leucine supplement. Although available in stand-alone supplement form, it is best taken with isoleucine and valine. Therefore, it is more convenient to choose a blended supplement.

6. But like anything, excessive leucine intake can also cause side effects, and high intake is known to be associated with problems such as pellagra, vitamin A deficiency, and can cause dermatitis, diarrhea, mental disorders, and other problems. Too much leucine in the diet can also increase the amount of ammonia in the body and damage liver and kidney function. Therefore, people with impaired liver or kidney function should not take large doses of leucine unless they have consulted their doctor, as this can worsen their condition.