L-Carnitine for Weight Loss

L-carnitine is one of the most popular weight loss supplements available.  With over 18 thousand clinical studies proving its efficacy and benefits for a wide range of health concerns – from heart disease to mental function – this is one weight loss supplement which really deserves its good reputation.

Carnitine is a nonessential amino acid which is produced in our brains, livers, and kidneys.  “Nonessential” does not mean that this amino acid is not important for our daily functioning.  Nonessential amino acids are made by the body whereas essential amino acids cannot be made by the body and must be taken in from other sources. In order to make carnitine, our bodies use essential amino acids as well as various vitamins and iron.  L-carnitine is a synthetic version of carnitine which is made from the amino acids lysine and methionine.

The Role of Carnitine in the Body

Carnitine has many roles in the body but one of its main functions is to turn fatty acids into energy.  Every single cell contains mitochondria, structures that are basically the powerhouse of cells. They produce energy by taking in nutrients and turning them into energy through a process called cellular respiration.For weight loss, carnitine is particularly important because it helps fatty acids get turned into energy.  The carnitine transports the fatty acids into the cells where it is used by mitochondria. By increasing the amount of carnitine in your body, you will increase the amount of fatty acids which get used for energy, thus decreasing the amount of fat which gets stored on your body. Carnitine thus increases metabolic rate.

It is important to note that carnitine will only have an energy-enhancing effect on your body if your body also has adequate fatty acids to be transported to cells for energy use.  People taking L-carnitine supplements may need to take additional supplements containing fatty acids, like Omega 3’s.

Benefits of Carnitine

The more scientists study about carnitine, the more amazing this natural compound appears.  By helping the body turn fat into energy, you obviously get a boost to your energy levels (which can be used for exercise and fat loss).  Carnitine supports weight loss and management by increasing metabolic rate and some studies also show it has an appetite suppressing effect.  L-carnitine is one supplement which goes beyond just weight loss though and has benefits affecting nearly all aspects of the body.  There have been several studies that have looked for potential beneifts of L-carnitine such as:

  • increasing muscle mass
  • slowing the loss of bone mass
  • treating cardiovascular problems
  • improving kidney function
  • improving male fertility
  • improving treatment of type II diabetes
  • boosting immunity and fighting diseases like cancer
  • improving cognitive function
  • reducing LDL cholesterol levels

Sources of Carnitine

The body will produce carnitine by itself so it is not necessary to take a carnitine supplement.  However, there are numerous reasons why a person may not be naturally producing enough carnitine.  Certain amino acids and vitamins, like B3 and B6, are required for carnitine production and a deficiency could result in too little carnitine being made.  Carnitine is also found in foods, especially red meat, some fish, and dairy products. People on a vegetarian or vegan diet may find it very difficult to get adequate amounts of carnitine.  There are limited plant-based sources of carnitine and they have only negligible amounts of the amino acid compared to meat.  For example, 100 grams of beef will have about 95 mg of carnitine whereas avocado has just 2 mg.

Do You Need to Supplement with L-Carnitine?

Carnitine is the name for your body’s natural carnitine.  L-carnitine is the supplement form which is readily available at health food and supplement stores.  Note that you should not take any carnitine supplement which contains D-carnitine. Only L-carnitine is the form of the amino acid which your body can use.

Most people make or consume enough carnitine on their own and do not need to take a supplement.  However, some people may be at risk of a carnitine deficiency, like vegetarians and breast-feeding women.  As we age, our bodies seem to produce less carnitine so elderly people may benefit from taking carnitine.  Some of the symptoms of a carnitine deficiency include muscle cramps and chronic tiredness.

Even if you are not deficient in carnitine, taking an L-carnitine supplement may still give you weight-loss and overall health benefits. L-carnitine is considered incredibly safe for most people.  However, L-carnitine could worsen seizure disorders and hypothyroidism.  It may also interact with certain medicines, like blood thinners and thyroid medications.  If you have health problems or are pregnant, it is always best to check with your doctor before taking any weight loss supplement, even one considered as safe as L-carnitine.

The dosage amount of L-carnitine varies depending on a person’s needs. For weight loss, L-carnitine usually is taken in amounts of 1-3 grams daily divided into several dosages.  To get the best results from an L-carnitine weight loss supplement, you should take it about 30-60 minutes before exercising. For endurance training, use a form of L-carnitine which is released into the body slower, such as tablets instead of powders.


“Carnitine: The Science Behind a Conditionally Essential Nutrient.” Ods.od.nih.gov. Office of Dietary Supplements National Institutes of Health. N.d. Web.

Hagen, Tory M., et al. “Feeding acetyl-L-carntiine and lipoic acid to old rats significantly improves metabolic function while decreasing oxidative stress.” PNAS, 99;4 (2002): 1870-1875. Web.

“Carnitine (L-carnitine).” Umm.edu. The University of Maryland Medical Center. N.d. Web.


The content provided on this site is for informational purposes only. Our content is not medical advice and you should seek a licensed physician or health professional regarding all health issues. WEIGHTLOSS.US takes no responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, or application of medication which results from reading this site.