Health Benefits of Carnitine Supplementation

What is L-Carnitine? 

Carnitine, derived from an amino acid, is found in nearly all cells of the body. Its name is derived from the Latin carnus or flesh, as the compound was isolated from meat.

Carnitine plays a critical role in energy production. It transports long-chain fatty acids into the mitochondria so they can be oxidized (“burned”) to produce energy. It also transports the toxic compounds generated out of this cellular organelle to prevent their accumulation. Given these key functions, carnitine is concentrated in tissues like skeletal and cardiac muscle that utilize fatty acids as a dietary fuel. 

L-carnitine’s main role in your body involves mitochondrial function and energy production. In cells, it helps transport fatty acids into the mitochondria, where they can be burned for energy. About 98% of your L-carnitine stores are contained in your muscles, along with trace amounts in the liver and blood. It is believed to help increase mitochondrial function, which plays a key role in disease and healthy aging. 

Types of Carnitine

L-carnitine is the standard biologically active form of carnitine, which is found in your body, foods and most supplements. Some types are: 

  • D-carnitine. This inactive form may cause a carnitine deficiency in your body by inhibiting the absorption of other, more useful forms. 
  • Acetyl-L-carnitine. Often called ALCAR, this is possibly the most effective form for your brain. Studies suggest it may benefit people with neurodegenerative diseases.
  • Propionyl-L-carnitine. This form is well-suited for circulatory problems, such as peripheral vascular disease and hypertension. It may boost production of nitric oxide, which improves blood flow. 
  • L-carnitine L-tartrate. This is commonly added to sports supplements due to its rapid absorption rate. It may aid muscle soreness and recovery in exercise. 

For most people, acetyl-L-carnitine and L-carnitine seem to be the most effective for general use. However, you should always pick the form that’s best for your personal needs and goals.

What Foods Provide Carnitine? 

Different animal products like meat, fish, poultry and milk are the best sources. In general, the redder the meat, the higher its carnitine content. Some examples of the content of carnitine in several foods are: 

  • Beef steak (cooked 4 ounces): 56-162 mg.
  • Ground beef (cooked 4 ounces): 87-99 mg.
  • Milk (whole 1 cup): 8 mg.
  • Codfish (cooked 4 ounces): 4-7 mg. 
  • Chicken breast (cooked 4 ounces): 3-5 mg. 
  • Whole wheat bread (2 slices): 0.2 mg.

Absorption and Metabolism 

Adults eating mixed diets that include red meat and other animal products obtain about 60–180 milligrams of carnitine per day. Vegans get considerably less (about 10–12 milligrams) since they avoid animal-derived foods. Most (54–86%) dietary carnitine is absorbed in the small intestine and enters the bloodstream. 

Health Benefits of Carnitine 


A decline in mitochondrial function is thought to contribute to the aging process. Carnitine may be involved because its concentration in tissues declines with age and thereby reduces the integrity of the mitochondrial membrane.

Research in aged rats found supplementation with high doses of acetyl-L-carnitine and alpha-lipoic acid (an antioxidant) to reduce mitochondrial decay. The animals also moved about more and improved their performance on memory-requiring tasks. 

A meta-analysis of double-blind, placebo-controlled studies suggests that supplements of acetyl-L-carnitine may improve mental function and reduce deterioration in older adults with mild cognitive impairment and Alzheimer’s disease. The subjects were taking 1.5-3 grams/day of acetyl-L-carnitine for 3-12 months. 

Athletic performance

There is mixed evidence when it comes to its effects on sports performance. Some studies have found mild benefits associated with larger or more long term doses. The effect may be indirect and take weeks or months to appear. It may benefit: 

  • Recovery.
  • Muscle oxygen supply.
  • It may increase blood flow and nitric oxide production, helping delay discomfort and reduce fatigue.
  • May reduce muscle soreness after exercise. 

Type 2 Diabetes

Insulin resistance, which plays an important role in the development of type 2 diabetes, may be associated with a defect in fatty-acid oxidation in muscle. This raises the question of whether mitochondrial dysfunction might be a factor in the development of the disease. Increased storage of fat in lean tissues has become a marker for insulin resistance.

A recent analysis of two multicenter clinical trials of subjects with either type 1 or type 2 diabetes found that treatment with acetyl-L-carnitine (3 grams/day orally) for one year provided significant relief of nerve pain and improved vibration perception in those with diabetic neuropathy. 

Cardiovascular Health

Some studies demonstrate a potential for reducing blood pressure and the inflammatory process associated with heart disease. 

In one study, 2 grams of acetyl-L-carnitine per day resulted in an almost 10-point drop in systolic blood pressure. L-carnitine is also linked to improvements in patients with severe heart disorders, such as coronary heart disease and chronic heart failure.

End-stage renal disease and hemodialysis

Carnitine homeostasis (balance within the body) among individuals with renal diseases can be substantially impaired by several factors, particularly reduced synthesis and increased elimination of the compound by the kidneys as well as reduced intake from food due to poor appetite and consumption of fewer animal products. They can become carnitine deficiency and supplementation can improve anemia, muscle weakness and fatigue. 

A recent meta-analysis of these studies concludes that carnitine supplements may aid anemia management but not blood-lipid profiles.

Should You Take It? 

Your L-carnitine levels are influenced by how much you’re eating and how much your body is producing. 

Vegetarians and vegans should consider carnitine supplements because they restrict or avoid animal products and can become deficient. Older adults may also benefit from L-carnitine supplements. Research shows that your levels tend to decline as you age. 

In one study, 2 grams of L-carnitine reduced fatigue and increased muscle function in older adults. Other research reveals that acetyl-L-carnitine may also help boost brain health and function as you age. Also the risk increases if you have any type of chronic condition, such as diabetes, kidney disease and cirrhosis. 

If you want to start using this amazing supplement to help you with any of these benefits. Get yours today:


Rudy Mawer, MSc. (2018, Nov 6). L-Carnitine: Benefits, Side Effects, Sources and Dosage. Healthline. Retrieved from: