L-Carnitine is a natural, non-protein amino acid. Under normal circumstances nearly 75% of the L-Carnitine in the human body is received from food (meat, dairy products, fish) and 25% is synthesized in the organism. L-Carnitine has a fundamental role in the lipid metabolism. It participates in the Carnitine-palmitine shuttle, which is responsible for the transportation of the fatty acids through the mitochondrial membrane into the mitochondria. In the mitochondria the fatty acids are transformed into energy through the process beta oxidation. The higher concentration of L-Carnitine significantly speeds up the lipid metabolism, thus it eases the fat burning process in the organism already put in calorie deficit. The additional intake through supplementation is of crucial importance for weight loss programs as well as for muscle building programs, which require extraordinary efforts. The higher levels of L-Carnitine benefit the heart, during physical activity, because the main energy source for the myocard are the fatty acids.