In the human body, L-carnitine is formed from the amino acids lysine and methionine. It is primarily formed in the liver and kidneys, and to be used, it must be transported to other tissues in the body. The highest levels of L-Carnitine are observed in tissues that use fatty acids as fuel. These include skeletal and cardiac muscles. L-carnitine has demonstrated its abilities as an anti-aging agent. Additionally, its effects on athletic performance, weight regulation, treatment of Alzheimer's disease, Parkinson's, diabetes, and other neurological disorders are widely studied.

L-Carnitine is known as a weight regulation agent. Its function in the body is to transport fats to the stores for fat burning, where they are converted into energy.