how to burn fat l-carnitine supplement guide what's new
Energy Systems




Scientific Name:            L-Carnitine

Type of Nutrient:            Amino Acid

How Supplied:               Powder, Capsules,Tablet

Natural Source:             Meat (Beef, Mutton, Lamb)

Used for:                        Fat Loss, Energy

Legal status:                  OTC

Availability:                     Health food shops, gyms

Cost effectiveness:            *

Safety:                            Good.  NOTE: R-Carnitine - toxic

                                        D-Carnitine - toxic

                                        DL- Carnitine - toxic


            Fats provide about 50% of your energy during aerobic exercise and 80% of  your energy towards the end of long endurance events (Coyle E.F. J Nutr 1992; 122:788-801).  You have to be able to burn them freely.  Carnitine absolutely controls fat use because it forms the mechanism or transport system that moves the free fatty acids into the mitrochondria (furnace part of cell) where they are burned as fuel.  (Strack E et al Protides of the Biological Fluids.  New York: Elsevier, 1964:234)

            Branch chain Aminos and Pyruvate are oxidised in the energy cycle with the help of carnitine.  (Brewer J Physiol Rev 1983;63:1420-1480).

            Carnitine inhibits the accumulation of lactic acid in muscle (see Bicarbonate for Benefits of Lactic Acid buffering).  One recent study of patients with angina being supplemented with L-Carnitine showed the build-up of lactic acid during moderate exercise was reduced by half, and the duration of exercise was significantly increased.  (Brevetti G, et al Circulation 1988;77:767-773).

            Because of Carnitines roles in the above, the amount of circulating carnitine in your muscles plays a major part in their efficiency and the amount of energy they can supply.

            The standard textbook response is that a sedentary person on a good diet doesn’t need to take L-carnitine because the body manufactures carnitine from the amino acids lysine and methionine (plus Vitamin C, niacin, pyridoxine, and iron).

            But athletes in heavy training put their bodies in a state of stress that uses heaps of carnitine.

            Their demand can easily exceed the bodies ability to make it (Lennon DLF, et al J Appl Physiol 1983;55:489).

            Moderate exercise, such as cycling on an ergometer bicycle at only 55% of VO2 max, causes a 20% drop in muscle carnitine (Lennon DLF, et al J Appl Physiol 1983;55:489).

            A much greater drop is caused by maximal exercise (Siliprandi N, et al Biochem Biophys Actu 1990;1034:17-21) putting athletes into the same carnitine status as patients with carnitine deficiency diseases.


            Physiological studies show that carnitine supplements inhibit the decline in free carnitine in muscle caused by maximal exercise, and completely prevents the decline in free carnitine during endurance exercise.  (Arenas J, et al Muscle and Nerve 1991;14:598-604).  There is evidence that L-carnitine can boost both anaerobic and aerobic performance.



            A dose of 2-4 grams taken for 2 weeks, one hour before exercise appears to be effective.

            This daily dose of L-carnitine shows no toxicity but DL-carnitine is TOXIC and must never by confused with L-carnitine, as they are two quite different compounds.