L-Carnitine is a naturally occurring compound that transports long-chain fatty acids into your mitochondria, where they're burned for energy. It's made in your body from the amino acids lysine and methionine, and it's found in red meat and dairy. For exercise, the most relevant form is L-Carnitine L-Tartrate (LCLT) — the form researched for muscle recovery, reduced exercise-induced damage, and fat oxidation during training. PurePump uses 500mg of Carnipure (branded LCLT from Lonza) per serving. Important caveat: L-Carnitine supports fat oxidation. It does not independently cause fat loss.