Carnitine comes in 4 different forms but only L-carnitine and Acetyl-L-carnitine (ALCAR) should be used by bodybuilders. Acetyl-L-carnitine (ALCAR) passes through the blood brain barrier better than L-carnitine, because it is acetylated. Therefore, it is the preferred form of carnitine. Carnitine is classified as an amino acid only because it is similiar in structure. In the body it is very different. Carnitine is not used as a pre cursor to making skeletal muscle in the body, like with regular amino acids. This makes it more useful, since supplementation won’t lead to it being used for protein synthesis instead of fat burning. If there is a deficiency of carnitine in the body, it will be synthesized from the amino acids methionione and lysine.

Does carnitine help burn fat?

One study was done on 20 rats published J Nutr 2000 Feb;130(2 :152-7. Both groups of rats excercised and ate similiar amount of calories. One group had carnitine, caffeine and choline and the other just had excercise. The results of the study showed no statistically significant difference between the groups.Keep in mind this study was done on rats.

Another study was done on humans, Metabolism. 2004 Aug;53(8 :1002-6. Twelve volunteers took 3grams of carnitine for 10 days on a regular diet. l-carnitine led to a dramatic increase in fat oxidation( Fat burning) while maintaining muscle (no decrease in protein catabolism). Another study was done on elderly men and they had a reduction in bodyfat, increased muscle and lower blood lip levels.

How does carnitine work on fat loss?

Carnitine helps shuttle free fatty acids into the mitochondria where they are burned off for energy. This is important because normally it is hard for the fatty acids to enter the mitochondria. This ultimately means more fat and less carbohydrates and protein, will be burned for energy in the mitochondria.

Any other uses for carnitine?

Carnitine also has been shown to have positive effects on mood and health in studies. Some of the results of the study showed improvement in ADHD, increasing fertilitiy, reducing recovery from excercise, reducing fatigue, curing depression, reversing hyperthyroidism, healing cirrhosis of the liver, sexual enhancement, increased cardiovascular health, removing toxins from the body, and many other conditions.

When to take Carnitine:

Many protein rich foods already contain carnitine. Carnitine is probably most effective when on a low calorie or low meat diet, where you won’t be getting as much carnitine in your diet. Bodybuilders may choose to take it year around, but just like with the case of glutamine, it may not prove to be very beneficial while bulking and already getting high amounts in your diet. Carnitine has been shown in studies to help reduce recovery and fatigue after excercise, which may be another reason to take it year around.

Carnitine side effects:

Doses beyond 100 to 500mg per day may cause insomnia and hyperactivity.