What is it? Overview Usage Side Effects and Warnings

What is Carnitine?

Carnitine is a substance used by the body uses to turn fat into energy. It is not normally considered an essential nutrient because the body can manufacture all it needs. However, supplemental carnitine could in theory improve the ability of certain tissues to produce energy. This has led to the use of carnitine for various muscle diseases as well as heart conditions.

Carnitine is primarily used for heart-related conditions. Some evidence suggests that it can be used along with conventional treatment for angina to improve symptoms and reduce medication needs. 1 2 3 4 5 When combined with conventional therapy, it may or may not help prevent medical complications or sudden cardiac death in the months following a heart attack . 6 7 Lesser evidence suggests that it may be helpful for a condition called intermittent claudication (pain in the legs after walking due to narrowing of the arteries), 8 9 10 11 12 13 14 15 16 17 as well as congestive heart failure . 18 In addition, a few studies suggest that carnitine may be useful for cardiomyopathy . 19 Carnitine may also be helpful for improving...

Safety Issues

L-carnitine in its three forms appears to be quite safe. However, individuals with low or borderline-low thyroid levels should avoid carnitine because it might impair the action of thyroid hormone. 20 Individuals on dialysis should not receive this (or any other supplement) without a physician's supervision.

The maximum safe dosages for young children, pregnant or nursing women, or those with severe liver or kidney disease have not been established.

Interactions You Should Know About

If you are taking:

  • Antiseizure medications, particularly valproic acid (Depakote, Depakene) but also phenytoin (Dilantin) : You may need extra carnitine.
  • Thyroid medication: Do not take carnitine except under a physician's supervision.