Carnitine Usage

Carnitine is best known and researched as an energy-boosting substance. The body uses it to turn fat into energy. Supplemental carnitine is used to improve the ability of certain tissues, such as...

Read more about Erectile Dysfunction and Carnitine.

Acetyl-L-Carnitine is a substance used by the body uses to turn fat into energy. Acetyl-L-Carnitine, in theory, could improve the ability of certain tissues to produce energy, including brain tissue...

Read more about Alzheimer's Disease and Acetyl-L-Carnitine (ALC).

Carnitine plays a role in the cellular production of energy. Although carnitine does not address the cause of angina, it appears to help the heart produce energy more efficiently, thereby enabling it...

Read more about Coronary Artery Disease (CAD) and Angina and L-Carnitine.

Early studies reported decreased carnitine levels in people with chornic fatigue syndrome.¹⁸ So naturally, supplementing it is thought to possibly help in the treatment of the condition.

Read more about Chronic Fatigue Syndrome (CFS) and Carnitine.

Carnitine may have a few effects on the heart after a heart attack, including helping to improve heart function and decreasing the enlargement that often follows an attack.

Read more about Heart Attack and L-Carnitine.

Carnitine is primarily used for heart-related conditions. Some evidence suggests that it can be used along with conventional treatment for angina to improve symptoms and reduce medication needs. ^{1 2 3 4 5} When combined with conventional therapy, it may or may not help prevent medical complications or sudden cardiac death in the months following a heart attack . ^{6 7} Lesser evidence suggests that it may be helpful for a condition called intermittent claudication (pain in the legs after walking due to narrowing of the arteries), ^{8 9 10 11 12 13 14 15 16 17} as well as congestive heart failure . ¹⁸ In addition, a few studies suggest that carnitine may be useful for cardiomyopathy . ¹⁹ Carnitine may also be helpful for improving exercise tolerance in people with chronic pulmonary obstruction disease (COPD), more commonly known as emphysema. ²⁰

Warning:You should not attempt to self-treat any of these serious medical conditions, nor should you use carnitine as a substitute for standard drugs.

Growing, if not entirely consistent, evidence suggests that L-carnitine or acetyl-L-carnitine, or their combination, may be helpful for improving sperm function and thereby provide benefits in male infertility. ^{21 22 23} Carnitine has also shown promise for improving male sexual function ²⁴ and improving mental and physical fatigue in seniors. ²⁵ Two studies found evidence that carnitine is helpful for Peyronie’s disease , a condition affecting the penis. ²⁶ Some studies have found evidence that one particular form of carnitine, acetyl-L-carnitine, might be helpful in Alzheimer's disease , ^{27 28 29 30 31 32} but the two most recent and largest studies found no benefit. ³³ One review evaluated published and unpublished double-blind, placebo-controlled trials, and concluded that acetyl-L-carnitine may only be helpful for very mild Alzheimer's disease. ³⁴ In preliminary trials, acetyl-L-carnitine has shown some promise for treatment of depression or dysthymia (a milder condition related to depression). ^{35 36} Some evidence suggests that carnitine may be useful for improving blood sugar control in people with type 2 (adult-onset) diabetes . ^{37 38} Better evidence suggests benefit with acetyl-L-carnitine for a major complication of diabetes, diabetic peripheral neuropathy (injury to nerves of the extremities caused by diabetes). ³⁹ Acetyl-L-carnitine might help prevent diabetic cardiac autonomic neuropathy (injury to the nerves of the heart caused by diabetes). ⁴⁰ However, one study found that carnitine supplements had an adverse effect on triglyceride levels in people with diabetes. ⁴¹ Much weaker evidence suggests possible benefits for neuropathy caused by the chemotherapy drugs cisplatin and paclitaxel. ⁴² Weak evidence hints that carnitine might help reduce liver and heart toxicity caused by the chemotherapy drug adriamycin . ⁴³ Some evidence suggests that carnitine may be able to improve cholesterol profile . ⁴⁴ One small study demonstrated a beneficial effect of L-carnitine on anemia and high cholesterol in patients on hemodialysis for chronic renal failure. ⁴⁵ A genetic condition called fragile X syndrome can cause behavioral disturbances such as hyperactivity, along with mental retardation, autism, and alterations in appearance. A preliminary study of 17 boys found that acetyl-L-carnitine might help to reduce hyperactive behavior associated with this condition. ⁴⁶ Evidence for the effectiveness of L-carnitine in attention deficit and hyperactivity disorder (ADHD) has been mixed. ⁴⁷ Celiac disease is an autoimmune disease affecting the digestive tract. Fatigue is a common symptom of the disease. One small double-blind trial found evidence that use of L-carnitine at a dose of 2 g daily might help alleviate this symptom. ⁴⁸ Weak evidence hints that carnitine may help people with degeneration of the cerebellum (the structure of the brain responsible for voluntary muscular movement). ⁴⁹ One very small study suggests carnitine may be helpful for reducing symptoms of chronic fatigue syndrome . ⁵⁰ Another study suggests that carnitine may be of value for treating hyperthyroidism ⁵¹ and for severe liver disease. ⁵² A substantial study marred by poor design (specifically, far too many primary endpoints) found equivocal evidence that L-carnitine, taken at dose of 500 mg three times daily, might be more effective than placebo for the treatment of fibromyalgia . ⁵³ Other weak evidence suggests that carnitine may be helpful for decreasing the muscle toxicity of AZT (a drug used to treat HIV infection ). ⁵⁴ Other weak evidence hints that the acetyl-L-carnitine might reduce nerve-related side effects caused by HIV drugs in general. ⁵⁵ One study failed to find carnitine effective for promoting weight loss , ⁵⁶ although another found that carnitine might lead to improvements in body composition (fat-muscle ratio). ⁵⁷ Carnitine is widely touted as a physical sports performance enhancer , but there is no real evidence that it is effective and some research indicates that it is not. ⁵⁸ Little to no evidence supports other claimed benefits such as treating irregular heartbeat, Down's syndrome, muscular dystrophy, and alcoholic fatty liver disease. However, in a randomized trial involving 25 patients with liver cirrhosis and early brain dysfunction (hepatic encephalopathy) associated with severe forms of this condition, carnitine appeared to significantly improve the function of both the liver and the brain after 3 months of treatment. ⁵⁹