L-CARNITINE - Watsons Health


L-carnitine is an amino acid (a building block for proteins) that is naturally produced in the body.

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.

Recent studies suggest that high concentrations of L-carnitine may actually damage the heart. Talk to your doctor before taking L-carnitine if you have certain health conditions:

  • Peripheral vascular disease (PVD)
  • High blood pressure
  • Kidney disease
  • Liver disease or if drinking alcohol has damaged your liver
  • Diabetes
  • Seizures or a history of seizures

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.


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.



Be cautious with this combination

Acenocoumarol (Sintrom) interacts with L-CARNITINE

Acenocoumarol (Sintrom) is used to slow blood clotting. L-carnitine might increase the effectiveness of acenocoumarol (Sintrom) make the blood to clot too much. The dose of your acenocoumarol (Sintrom) might need to be changed.

Thyroid hormone interacts with L-CARNITINE

Taking L-carnitine with thyroid hormone might decrease the effectiveness of the thyroid hormone.

Warfarin (Coumadin) interacts with L-CARNITINE

Warfarin (Coumadin) is used to slow blood clotting. L-carnitine might increase the effects of warfarin (Coumadin) and increase the chances of bruising and bleeding. Be sure to have your blood checked regularly. The dose of your warfarin (Coumadin) might need to be changed.

The following doses have been studied in scientific research:

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

For preventing side effects caused by valproic acid (Depacon, Depakene, Depakote, VPA):  50 to 100 mg/kg/day in three or four divided doses, to a maximum of 3 grams/day.

For chest pain and congestive heart failure (CHF): 1 gram twice daily.

Following heart attack:  2 to 6 grams daily.

For symptoms of overactive thyroid: 1-2 grams twice daily.

For male infertility: 2 grams of L-carnitine plus 1 gram of L-acetyl-carnitine daily.


Available brands:

  • Cardimax (Integrated Pharma)
  • Carnicor (PPC)
  • Cartine
  • Zeman SX (Metrodrug)
  • Nestogen 1

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