L-carnitine is a chemical that is made in the human brain, liver, and kidneys, and it helps the body turn fat into energy. It is important for heart and brain function, muscle movement, and many other body processes. L-carnitine is used to increase L-carnitine levels in people whose natural level of L-carnitine is too low. Some people also use L-carnitine for conditions of the heart and blood vessels, serious kidney disease, and many other conditions, but there is no good scientific evidence to support these uses. Here are some of the uses and effectiveness of L-carnitine:

• Effective for: L-carnitine deficiency. Taking L-carnitine by mouth or by IV is effective for treating L-carnitine deficiency caused by certain genetic diseases or other disorders.

• Possibly effective for: Chest pain (angina). Taking L-carnitine by mouth or by IV seems to improve exercise tolerance in people with chest pain. Taking L-carnitine along with standard treatment also seems to reduce chest pain and improve exercise ability in people with cardiac syndrome X. High levels of cholesterol or other fats (lipids) in the blood (hyperlipidemia). Taking L-carnitine by mouth or by IV can improve cholesterol and triglyceride levels.

• May be effective for: Heart failure. A few small studies have suggested that carnitine (usually propionyl-L-carnitine) can help reduce symptoms of heart failure and improve exercise capacity in people with heart failure. Peripheral Vascular Disease. Although carnitine is often taken to boost exercise performance, more research is needed. Weight Loss. Although L-carnitine has been marketed as a weight loss supplement, scientific evidence is lacking.

It is important to note that L-carnitine should be used along with conventional medication under a healthcare providers supervision.