L-carnitine is an amino acid (a building block for proteins) that is naturally produced in the body.
- L-carnitine supplements are used 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 used as a replacement supplement in strict vegetarians, dieters, and low-weight or premature infants.
- L-carnitine is used 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, leg pain caused by circulation problems (intermittent claudication), and high cholesterol.
- Some people use L-carnitine for muscle disorders associated with certain AIDS medications, difficulty fathering a child (male infertility), a brain development disorder called Rett syndrome, anorexia, chronic fatigue syndrome, diabetes, overactive thyroid, attention deficit-hyperactivity disorder (ADHD), leg ulcers, Lyme disease, and to improve athletic performance and endurance.
- 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 helps the body produce energy. It is important for heart and brain function, muscle movement, and many other body processes.
- 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 POSSIBLY 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.
- 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.
3-carboxy-2-hydroxy-N,N,N-trimethyl-1-propanaminium inner salt, (3-carboxy2-hydroxypropyl) trimethylammonium hydroxide inner salt, 3-hydroxy-4-N-trimethylaminobutyrate, B-hydroxy-N-trimethyl aminobutyric acid, Beta-hydroxy-gamma-trimethylammonium butyrate, B(t) Factor, Carnitine, Carnitor, D-Carnitine, DL-Carnitine, Facteur B(t), L-3-hydroxy-4-(trimethylammonium)-butyrate, Levocarnitine, Lévocarnitine, Levocarnitine Fumurate, L-Carnitina, L-Carnitine Fumarate, L-Carnitine L-Tartrate, L-Carnitine Tartrate, (R)-(3-carboxy-2-hydroxypropyl) trimethylammonium hydroxide, (R)-3-hydroxy-4-trimethylammonio-butyrate, Vitacarn, Vitamin B(t), Vitamine B(t).
Source: WebMD, “L-Carnitine”, www.webmd.com/vitamins-supplements/