L-carnitine is one  semi-essential protein compound  of the two essential amino acids methionine and lysine. However, sufficient methionine and lysine must be available for the body to produce its own L-carnitine  be. In food, it is mainly found in red meat, which is why vegans and vegetarians in particular should make sure they get enough.
 L-carnitine is primarily related to fat metabolism because, as a protein compound, it transports long-chain fatty acids to the mitochondria. Mitochondria are considered the "power plants of the cell" where the fatty acids are converted into energy in the so-called β-oxidation process. Therefore, L-carnitine is often associated with high-performance sports.