WHAT IS L-CARNITINE?

While it is often categorised as an amino acid, L-Carnitine isn’t technically an amino. It is considered a “vitamin-like” and “amino acid-like” compound that is related to the B vitamins.

L-carnitine is formed in the liver and kidneys from the amino acids lysine and methionine. However, it is stored elsewhere in the body, primarily in muscle (including the heart), the brain, and even in sperm. In the diet, it mainly comes from meat and other animal products. You can get some from plant products like avocado and soybeans, but as a rule, meat is the best source—and the redder the better.

Acetyl L-carnitine, also known as acetyl carnitine or ALCAR, is another popular supplemental form of L-carnitine. It can be found throughout the central nervous system, where it plays a role in producing energy, as well as producing the important neurotransmitter acetylcholine.

WHAT DOES L-CARNITINE DO?

The most critical role that it plays in the body is helping to transport fat, particularly long-chain fatty acids, into the mitochondria of cells. Once there, they can be oxidized—used as fuel—to generate adenosine triphosphate, or ATP.

Without adequate L-carnitine, most dietary fats can’t get into the mitochondria and be burned for fuel. But for people with a deficiency it is a serious medical condition whose implications don’t stop at being unable to burn body fat. It can lead to muscle weakness, stunted growth, an enlarged liver, and several other problems. This is one reason it is considered a “conditionally essential” nutrient: Your body produces it, but if it doesn’t produce enough, your health can be seriously impacted.

ARE THERE ANY SIDE EFFECTS?

There are few negative side effects from supplementation at reasonable doses. It can cause nausea, abdominal cramps, vomiting, and diarrhea when taken in really high doses.

HOW MUCH TO TAKE

While as little as 1 gram  can be effective, your best bet is to take 2-3 grams per dose for maximum benefit.

SHOULD YOU CYCLE IT?

At this point in time it appears that there is no need to cycle on and off. Taken regularly, it should continue to be effective long-term.

WHEN SHOULD IT BE TAKEN?

Acetyl-L-carnitine is more easily taken up by the intestines and the muscle cells, not to mention the brain, in the absence of food. Therefore, this form may be stacked with other ingredients that enhance fat-burning, such as caffeine and green tea, and taken first thing in the morning or between meals.