L-Carnitine

L-carnitine is an amino acid that is naturally produced in the body. L-carnitine helps the body turn fat into energy. The body can convert L-carnitine to other amino acids called acetyl-L-carnitine and propionyl-L-carnitine. But, no one knows whether the benefits of carnitines are interchangeable. Until more is known, don't substitute one form of carnitine for another.

L-carnitine supplements are taken by mouth to increase L-carnitine levels in people whose natural level of L-carnitine is too low because they have a genetic disorder, are taking certain drugs (such as valproic acid for seizures or certain antibiotics for tuberculosis), or because they are undergoing a medical procedure (hemodialysis for kidney disease) that uses up the body's L-carnitine. It is also used as a replacement supplement in strict vegetarians, dieters, and low-weight or premature infants.

L-carnitine is taken by mouth for conditions of the heart and blood vessels including heart-related chest pain, congestive heart failure (CHF), heart complications of a disease called diphtheria, heart attack, heart disease, leg pain caused by circulation problems (intermittent claudication), reduced circulation in the arms and legs due to narrowed blood vessels (peripheral vascular disease), irregular heartbeat, and high cholesterol.

Some people use L-carnitine by mouth for muscle disorders associated with certain AIDS medications, difficulty fathering a child (male infertility), a brain development disorder called Rett syndrome, anorexia, body weakness and wasting due to an illness, weight loss, chronic fatigue syndrome and fatigue associated with multiple sclerosis, celiac disease, cancer, aging, diabetes, metabolic syndrome, overactive thyroid, attention deficit-hyperactivity disorder (ADHD), autism, leg ulcers, Lyme disease, a blood disorder called beta-thalassemia, loss of brain function due to liver damage, hepatitis C, non-alcoholic liver disease, memory, migraine headache, to improve athletic performance and endurance in healthy people and people with a lung condition called chronic obstructive pulmonary disease (COPD). It is also taken by mouth for narcolepsy and for spinal muscle weakness in children.

L-carnitine us given intravenously (by IV) to increase L-carnitine levels in people whose natural level of L-carnitine is too low because they have a genetic disorder, are taking certain drugs (valproic acid for seizures), or because they are undergoing a medical procedure (hemodialysis for kidney disease) that uses up the body's L-carnitine. It is also given by IV to improve immune function in people with HIV/AIDS, and to people who have had a heart attack. It is also used as a supplement for people on a feeding tube, and in low-weight or premature infants with breathing problems.

L-carnitine is applied to the skin for acne and hair loss.

L-carnitine is also used in eye drops for dry eyes.

How does it work?

L-carnitine helps the body produce energy. It is important for heart and brain function, muscle movement, and many other body processes.

L-carnitine deficiency.
Chest pain (angina).
Heart failure.
Serious kidney disease.
High thyroid hormone levels (hyperthyroidism).
Male infertility.
Inflammation of the heart (myocarditis).
Preventing side effects caused by valproic acid (Depacon, Depakene, Depakote, VPA), a seizure medication.

By Mouth:

For L-carnitine deficiencies: 990 mg two to three times daily in tablets or as an oral solution.

For chest pain (angina): Doses of 900 mg to 2 grams of L-carnitine have been taken in one to two divided doses daily for 2 weeks to 6 months.

For heart failure: 1.5 to 3.0 grams of L-carnitine has been taken in one to two divided doses daily for up to about 34 months. A specific product (Carni Q-Gel, Tishcon Corporation,Westbury, NY) containing 2250 mg of carnitine and 270 mg of coenzyme Q10 has been taken daily for 12 weeks.

For people with serious kidney disease undergoing hemodialysis: Doses of 0.64-3 grams or 10 mg/kg of L-carnitine has been used daily for 3-52 weeks. Taking L-carnitine by mouth is not FDA approved to treat carnitine deficiency in people with serious kidney disease.

For high thyroid hormone levels (hyperthyroidism): 2-4 grams of L-carnitine has been taken daily for 2-4 months.

For male infertility: 2-3 grams of L-carnitine has been taken in up to three divided doses daily, with or without vitamin E, for 2 to 24 weeks. Also, 2 grams of L-carnitine plus 1 gram of acetyl-L-carnitine has been taken daily, with or without a 300 mg cinnoxicam suppository every 4 days, for 3-6 months.

For inflammation of the heart (myocarditis): 100 mg/kg of D,L-carnitine has been taken daily for 4 days.
For preventing side effects caused by valproic acid (Depacon, Depakene, Depakote, VPA): 50 to 100 mg/kg has been taken in three or four divided doses daily up to a maximum of 3 grams daily.

By IV:

For chest pain (angina): An infusion of 3 grams of L-carnitine in 500 mL of 5% dextrose has been given once daily for 14 days. 40mg/kg of D,L-carnitine has also been given by IV 30 minutes before exercise.

For L-carnitine deficiencies: Doses of 50 mg/kg of L-carnitine have been given as a slow injection or by infusion followed by 50 mg/kg of L-carnitine in divided doses every 3 to 4 hours over the next 24 hours. In the following days, daily maintenance doses are usually in the range of 50 mg/kg. For people with L-carnitine deficiency related to hemodialysis, 10 to 20 mg/kg of L-carnitine adjusted for L-carnitine blood levels is used.
For heart failure: 5 grams of L-carnitine has been given by IV daily for 7 days in addition to conventional treatment.

For serious kidney disease: Doses of 10 to 20 mg/kg of L-carnitine given as a slow injection is FDA-approved for use for L-carnitine deficiency in people with serious kidney disease. For treating disorders related to low levels of carnitine in hemodialysis patients, 1.8 grams of L-carnitine weekly to 3 grams daily or 30-120 mg/kg/week have been given by IV for 2 weeks to 12 months. Doses were usually given three times weekly after dialysis sessions. Also, 1 gram of L-carnitine has been given by IV three times weekly after each dialysis session together with 100 mg of coenzyme Q10 taken by mouth daily for 3 months.

For preventing side effects caused by valproic acid (Depacon, Depakene, Depakote, VPA): 150-500 mg/kg has been taken daily. A maximum of 3 grams daily.

L-carnitine is SAFE when taken by mouth for up to 12 months, and when used as an injection, with the approval of a healthcare provider. It can cause side effects such as nausea, vomiting, stomach upset, heartburn, diarrhea, and seizures. It can also cause the urine, breath, and sweat to have a "fishy" odor.

Avoid using D-carnitine and DL-carnitine. These forms of carnitine might block the effects of L-carnitine and cause symptoms that resemble L-carnitine deficiency.

Pregnancy and breast-feeding: There is not enough reliable information about the safety of using L-carnitine if you are pregnant. Stay on the safe side and avoid use.

Taking L-carnitine is SAFE in breast-feeding women when taken by mouth in the amounts recommended. Small amounts of L-carnitine have been given to infants in breast milk and formula with no reported side effects. The effects of large amounts taken by a breast-feeding mother are unknown.

Children: L-carnitine is POSSIBLY SAFE when used appropriately by mouth or intravenously (by IV), short-term. It has been used safely by mouth for up to 6 months.

Under-active thyroid (hypothyroidism): Taking L-carnitine might make symptoms of hypothyroidism worse.

Kidney failure: Using DL-carnitine has been reported to cause symptoms such as muscle weakness and eye drooping when administered intravenously (by IV) after dialysis. L-carnitine does not seem have this effect.

Seizures: L-carnitine seems to make seizures more likely in people who have had seizures before. If you have had a seizure, do not use L-carnitine.