L-carnitine, or carnitine, is a compound that is of vital importance for the body to produce energy. Carnitine is also a recognized fat burner that works directly on the part of the cell that burns fat in the body. It has been used to treat several ailments in both prescription and supplement form, and is generally considered safe for most use.
In the body
L-carnitine is derived from both L-lysine and methionine amino acids. It is mainly manufactured in the liver and kidneys, however, it can be found in both the skeletal and cardiac muscles. It can also be found anywhere in the body that uses fatty acids as dietary fuel.
Carnitine supplements, and derivatives of L-carnitine, have been used by medical professionals to treat several ailments. L-carnitine is used to treat angina pectoris, heart attack, heart failure, Alzheimer's disease, diabetes, hyperthyroid and HIV infection.
Some studies have suggested that L-carnitine may prevent the decline in both energy metabolism and memory. The preventative ability of carnitine to sustain energy metabolism is one reason why carnitine has been chosen as a weight loss aid.
Normal levels of carnitine do not typically have any side effects, however, if carnitine levels become elevated there may be some side effects. Sleeplessness, vomiting, nausea, headache, diarrhea and a stuffy nose are some of the less serious side effects. Serious side effects include fast heartbeats, an increase in blood pressure and fever.
L-carnitine should not be taken by people who have low or borderline thyroid levels, because carnitine has been shown to impair the function of the thyroid hormone.
Carnitine supplements are the best way to add carnitine into the diet. The suggested dosage is 500 to 1,000 mg daily. Supplements can be found in capsules, powders and tablets. For each form the dosage is consistent, and it is recommended that the supplements are taken with food.
While most people generally consume enough carnitine in their daily diet, food sources rich in carnitine can also be added into the diet to boost carnitine levels. Carnitine can be found in many foods, but red meats like beef and lamb are the best choices for adding carnitine into the diet. Fish, poultry and milk also are good carnitine sources.