Carnitine, C₇ H₁₆ NO₃⁺ is an essential molecule in the body's metabolic processes. It's precursors are the amino acids lysine and methionine. It plays a role in a multitude of pathways.

Fatty-Acid Transporter: Carnitine shuttles long chain fatty-acids across the inner-mitochondrial membrane, so they can there be metabolized.

Toxin removal: Carnitine plays a role in shuttling harmful toxins out of the body.

CoA Buffer: Carnitine helps to maintain an adequate concentration of free CoA by reacting with the acyl groups of acylCoA.

Membrane Repair: Carnitine appears to provide activated fatty acids to enzymes that remove damaged fatty acids from membrane phospholipids and replace them with the fatty acid obtained from carnitine. Most of these studies use red blood cells.