Muscle fatigue. Chronic fatigue syndrome. Fatigue from chemotherapy and radiation. You name the type of fatigue that’s plaguing you and I’ve got just the supplement for you. I’ll even bet that you haven’t heard about it before. It’s called L-carnitine, the most bioavailable form of carnitine, a vitamin-like constituent of protein that can boost energy naturally and safely. In addition to regular exercise and/or balancing hormones, I often recommend L-carnitine to my patients. It energizes both the body and the mind, and it gives people a “get up and go” feeling.

HOW CARNITINE WORKS

Carnitine plays a crucial role in how cells make energy. Most people think of glucose (blood sugar) as the body’s main fuel. But we also burn fat for energy. Think of carnitine as the transport system that shovels fat into the fire for burning. The fat burning is a process that fuels your heart cells and muscle cells. The more fuel your heart and muscles have, the more energy you’ll have. With added carnitine, your body can increase its ability to burn fat for energy.

There are several ways we can get carnitine. First, our bodies manufacture it from the amino acids lysine and methionine in concert with other nutrients, including vitamin C, B vitamins and iron. Carnitine also is available through diet, mainly from meat, specifically red meat (although I don’t advise patients to get their carnitine from meat, which is not as healthful as other foods). Lastly, you can take L-carnitine supplements. L-carnitine often is confused with another supplement, acetyl-L-carnitine (ALC). These cousin energy-boosters can be converted to one another in the body. While ALC is believed to help the brain, L-carnitine helps the body.

GET MORE ENERGY

L-carnitine’s energy-boosting benefits have been well-documented. In one study published in The American Journal of Clinical Nutrition, researchers gave centenarians two grams of L-carnitine or a placebo for six months. Those taking L-carnitine had impressive increases in physical and mental energy, as well as improvements in cognition and muscle mass.

Nearly everyone can get an energy boost from this supplement, because most of us don’t make enough carnitine in our own bodies or don’t get sufficient amounts from food. Deficiencies of vitamins B and C, for instance, interfere with the body’s production of carnitine.

So, who is at particular risk for low carnitine levels? Since vitamin C plays a key role in making carnitine, if you don’t eat many vegetables and fruits or take supplements, you may not be making enough carnitine. Having elevated blood levels of triglycerides, a type of fat that increases the risk for heart disease, also may be a sign of low carnitine.

RELIEVING DIFFERENT FORMS OF FATIGUE

Studies have found that L-carnitine supplements combat fatigue regardless of its origin…

General fatigue. I often suspect that patients have a deficiency of carnitine when they complain of muscle fatigue and cramps. Since it is safe to take, I usually give patients the supplement to see if it helps them. When a patient has a severe carnitine deficiency that has lasted for two or three months or more, other symptoms may include low blood sugar and cardiovascular disorders (such as angina or heart arrythmia) in addition to fatigue.

Chronic fatigue syndrome (CFS). Researchers at Mercy Hospital and Medical Center in Chicago used either 3,000 milligrams (mg) of L-carnitine or the drug amantadine (Symmetrel), which is used to combat fatigue in adults with CFS. L-carnitine supplements led to improvements in all 18 of the tests that the doctors used to measure the severity of CFS symptoms—and symptom improvement in 12 of the tests was significant. The drug did not lead to any improvements at all.

Chemotherapy and radiation. L-carnitine can reduce fatigue caused by these cancer treatments. In one study published in Nutrition, doctors gave supplements of L-carnitine to adults undergoing treatments for various types of cancer, including those of the head and neck, breast, ovary, uterus and stomach. Taking 2,000 mg of L-carnitine three times daily for four weeks led to significant reductions in fatigue, improved appetites and muscle mass, and better overall quality of life.

DOSING

If you are generally healthy but want to increase your energy levels, try 500 mg to 1,000 mg of L-carnitine daily. For those who feel tired much of the time, the dosage I usually recommend is 2,000 mg daily. For better absorption, divide these doses into two or three smaller ones during the day with meals. (Some people take greater amounts of L-carnitine under a doctor’s supervision as in the studies mentioned above, but I believe that 2,000 mg is the maximum that can be absorbed in one dose.) L-carnitine is safe for everyone. Some people experience digestive upset, but if you take the supplement with meals or reduce the dose, this usually goes away. If you continue to feel tired after taking L-carnitine, ask your physician to investigate further.