Carnitine
(Levocarnitine, L-carnitine, Carnitor)
What is it?
Carnitine is a naturally occurring amino acid derivative your body must have to metabolize energy and for the proper use of fats.
Does it occur naturally in the body?
Yes.
What are the claims?
Carnitine and L-carnitine are marketed as a treatment for dementia and congestive heart failure, to alleviate depression and as a natural fat burner.
Companies marketing it for bodybuilders claim that carnitine acts as a "fat burner" by optimizing fat oxidation and reducing its availability for storage.
Does it work?
No.
There are surprisingly few studies to test the effectiveness of carnitine, but one of the most thorough performed (in part) by Marcelo Saldanha Aoki at the Institute of Biomedical Sciences came to this conclusion:
"Our results indicate that carnitine feeding, per se, failed to promote fat mass loss...Our data strongly suggest that endurance training, rather than carnitine content, is the major factor involved in fat mass loss."
(The study is from the Annals of Nutrition & Metabolism, Vol. 48, No. 2, 2004.)
What are the dangers?
Nausea, vomiting, stomach ache, diarrhea, body odor or muscle weakness. Large doses of carnitine taken by mouth for long periods of time may result in serious side effects, specifically seizures.
The Bottom Line
As of the date this article is posted, we have not been able to find any studies showing a benefit for bodybuilders or people trying to lose fat. In addition there are potentially serious side effects.
Unless prescribed by a doctor for a medical condition, we cannot recommend the supplement carnitine.
