Your body uses L-carnitine to convert fat into energy. A substance found naturally in the body, it is important for heart and brain function, muscle movement, and many other body processes. Because of its role in breaking down fat, body builders use the substance for weight loss or to improve muscle function.

L-carnitine also acts as an antioxidant, helping the body fight harmful molecules called free radicals, which damage your cell’s DNA. Free radicals have been linked to premature aging and cancer. As an antioxidant, L-carnitine is used for conditions of the heart and blood vessels such as heart-related chest pain, congestive heart failure (CHF), diphtheria, heart attack, etc. L-carnitine is also used for fatigue or to boost athletic performance.

A brief overview
L-Carnitine can simply be referred as carnitine. It is a form of amino acid, which is naturally produced and stored in the body. The liver and kidneys are the organs that manufacture this substance. Storage occurs in the skeletal muscles, heart, brain, and sperm.

Normally, the body can make all the carnitine it needs. Some people may have a deficiency because the body may not be able to transport carnitine into the tissues. There are also some health conditions that can result from low levels of carnitine, including angina and leg cramping (medically known as intermittent claudication).

Because of its role in breaking down fat and building muscle mass, L-carnitine is also recommended for strict vegetarians, dieters, and low-weight or premature infants.

Active reagents in L-Carnitine
The biological active reagent in carnitine is L-carnitine. L-Carnitine is responsible for transporting fat to the mitochondria for oxidation in our cells. Oxidation is the process of breaking down fats to obtain usable energy. By boosting muscle metabolism, and aiding the mitochondria in breaking down fats, L-carnitine has become known as a heart protector.

Carnitine is an antioxidant. An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. As an antioxidant, L-carnitine fights harmful particles in the body known as free radicals, which damage cells and tamper with DNA.

Benefits of L-Carnitine

Increasing red blood cells –  The kidney manufactures red blood cells.  People suffering from kidney disorders have a low number of red blood cells. It has been proven that L-carnitine can be used to bolster red blood cell counts in people with kidney disease.
Improving low birth weight: – Infants born prematurely receive more benefit from the nutrition they get in the hospital when they are also given L-carnitine by mouth or intravenously.
Weight Loss – L-carnitine is widely used as a weight loss supplement. It helps increase your muscle mass, which boosts your metabolism, encouraging weight loss. And more muscle burns more calories, as you need four to five times more calories to build muscle tissue than maintaining fat tissue. Several studies show that oral carnitine may reduce fat mass in the body. It has also been shown that L-Carnitine improves lean muscle strength. However, some doctors and dieticians disagree with its efficacy as a weight loss supplement citing studies that show that it works no better than a placebo.
Removal of fats – L-Carnitine also helps remove fats waste products (ketones) from the blood stream. It helps to discourage fatty build up in the liver, heart, and skeletal muscle.
Treatment and prevention of L-carnitine deficiency –  L-carnitine deficiency can have a number of causes; failure of the body to manufacture enough carnitine, the body not being able to transport carnitine to the tissues, and certain diseases and some medical procedures. The US Food and Drug Administration (FDA) approved L-carnitine for treating and preventing L-carnitine deficiency.

Angina – Several studies indicate that carnitine can be used as a complementary treatment for moderate angina. Clinical trials have shown that L-carnitine and propionyl-L-carnitine can help reduce symptoms of angina. Carnitine has also been seen to improve the ability of people with angina to exercise without chest pain. However, do not self medicate angina with carnitine. See your doctor for diagnosis and conventional treatment. You should only take carnitine under your health care provider’s supervision.
Heart attack Risk – A few studies have found that carnitine may help when used with conventional medicines after a heart attack. It is suggested, by some small studies, that people who take L-carnitine supplements soon after a heart attack may be less likely to have another heart attack. They are also less likely to die of heart disease, have chest pain, abnormal heart rhythms, or develop heart failure. Treatment with oral carnitine may also improve muscle weakness. Carnitine supplements should be used along with conventional medication under the supervision of your health care.
Heart failure – People with heart failure have limited ability to exercise, lacking in energy and quickly becoming breathless. A few studies have suggested that L-carnitine supplements can help reduce symptoms of heart failure and improve the ability to exercise properly in people with heart failure. However further studies are needed for confirmation.
Leg Cramping and peripheral vascular disease – Atherosclerosis or hardening of the arteries is a disorder that leads to decreased blood flow to the legs. This condition often causes an aching or cramping pain in the legs while walking or exercising. This pain is called intermittent claudication, and the reduced blood flow to the legs is called peripheral vascular disease (PVD). Several studies have shown that carnitine supplements can help reduce symptom of atherosclerosis and increase the distance that people with intermittent claudication (leg cramping) can walk.
Erectile Dysfunction – Preliminary studies have suggested that propionyl-L-carnitine may help improve male sexual function. One health study found that carnitine supplements improved the effectiveness of sidenafil (Viagra) in men with diabetes who had not previously responded to Viagra. Additionally, another study showed that, a combination of propionyl-L-carnitine and acetyl-L-carnitine improved the effectiveness of Viagra in men who had erectile dysfunction after prostate surgery.

Naturopathic doctors use carnitine for several other conditions including diabetic neuropathy, Alzheimer’s Disease and Memory Impairment, Kidney Disease and Dialysis, Male infertility, Peyronie’s Disease, Hyperthyroidism etc. While there is anecdotal evidence to support these uses, more research is needed to scientifically establish its efficacy for these conditions.

Side effects
Under-active thyroid (hypothyroidism) – The use of L-carnitine might make symptoms of hypothyroidism worse.
Seizures – The use of L-carnitine seems to make seizures more likely in people who have had seizures before. If you have had a seizure, you are advised not to use L-carnitine.
Diarrhea – High doses (5 or more grams per day) of carnitine may cause diarrhea.
Increased appetite – Some users of carnitine may experience increased appetite.
Body odor – Carnitine supplements can also cause the urine, breath, and sweat to have a “fishy” odor.
Nausea – Nausea, vomiting, stomach upset and heartburn may also be experienced. Some people who use carnitine may get a rash on their bodies. This is a rare side effect, more likely in those taking high doses.

Carnitine is an important substance in the human body. Its key use is in helping to break down fat, and convert it to energy through oxidation. Carnitine is most commonly used for weight loss. It helps increase your muscle mass, which boosts your metabolism, encouraging weight loss. And more muscle burns more calories, as you need four to five times more calories to build muscle tissue than maintaining fat tissue. Carnitine is also an antioxidant. However, there are side effects from this substance, so it’s best to consult with a health care professional before taking carnitine.