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Last updated on September 13th, 2023 at 10:12 am

Do You Know What is L-Carnitine?

L-Carnitine is a naturally occurring compound that is derived from the amino acid lysine and methionine. It is present in every cell of the body and functions as a carrier to transport activated fatty acids into the mitochondria and helps in energy production. In mitochondria, it is needed for beta-oxidation of acyl-CoA esters which are formed as a result of the breaking down of fatty acids.

As a chemical compound, L-Carnitine was first isolated from meat by a Russian scientist Gulewitsch in 1905. Initially, it was named Vitamin BT as it was observed that in mealworms (Tenebrio molitor) it acted as a vitamin however that was later changed in 1927 by two researchers Fritz and Bells who renamed it Carnitine. As more research continued several carnitine-derived compounds were found however only the L-isomer of Carnitine (L-carnitine, acetyl-L-carnitine, and propionyl-L-carnitine) is bioactive for humans.

L-Carnitine is a vitamin for babies who receive it from milk however for adults it is not a vitamin as it can be synthesized from the amino acids in the brain, kidneys, and liver which helps in maintaining carnitine homeostasis in the body. The demand for L-carnitine increases in conditions where the body is unable to process it from amino acids, making it an occasional essential nutrient.

Apart from being essential for the production of ATP in the body for energy, L-carnitine has been documented to have other benefits as well. It is needed for proper cardiovascular function which also translates to better exercise performance as well as for muscle strength and function. Additionally, it also helps transport waste products out of mitochondria and it is present in non-mitochondrial cells as well including red blood cells. Most of the L-carnitine in the body is stored in the muscles and other organs including the testes, liver, and kidneys.

Let’s Discuss the Benefits of L-Carnitine

As an amino acid derivative L-carnitine is also referred to as Health carnitine as it not only helps in the production of energy by helping the transport of fatty acids but also it strengthens the mitochondrial structure by removing mitochondrial waste. L-carnitine exhibits anti-oxidant properties which help protect against cell damage. It also helps in the production of nitric oxide and acts as a neurotransmitter modulator which gives it several health benefits making it indispensable for good health and essential for proper body function.

L-Carnitine Dosage for Weight Loss

The primary function of L-carnitine has been identified as to transport fatty acids to mitochondria for oxidation which is then used to convert into energy in the form of ATP. This function of L-carnitine can help those who are looking to lose weight when combined with low caloric intake along with exercise and weight-loss medication by increasing fat metabolism in the body.

On its own supplementation with L-carnitine has minimal effect on weight loss however if combined with weight loss medication and a restrictive diet it shows promising results.
In a year-long randomized research study patients were divided into random groups where one group was given 2 grams of L-carnitine along with a prescription medication while the other group was only given the prescription medication. The group which was given L-carnitine showed faster and higher weight loss than the group which was just given the prescription medication. Additionally, it also improved insulin resistance and other inflammatory parameters in the group which took L-carnitine.

This study is further supported by a 2016 meta-analysis of 9 clinical trials where L-carnitine was given to obese patients in combination with other methods in different doses (1.8-10+grams a day) which resulted in observable weight loss and BMI changes.

L-Carnitine for Cardiovascular Function

The human heart is one of those organs which constantly needs energy to function, l-carnitine helps myocardial mitochondria by transporting fatty acid cells to be converted into energy (ATP), this ensures proper heart function. Supplementation with L-carnitine may also help in heart issues such as heart failure, angina, and ischemic heart disease. Additionally, the anti-oxidant properties of L-carnitine also help protect the heart and its cells from oxidative stress and other inflammation-related cardiovascular issues such as coronary artery disease, atherosclerosis, and myocarditis.

In a meta-analysis of 13 control trials with 3500+ participants, it was observed that supplementation with L-carnitine when compared to control and placebo, resulted in a 27% reduction in all-cause mortality, 65% reduction in ventricular arrhythmias and a significant decrease in anginal symptoms (chest pains, shortness of breath, sweating, nausea, etc.) in patients suffering from acute myocardial infarction.

However, it is important to know that more trials and large-scale studies on the effects of L-carnitine on heart conditions are needed to better understand its effects on heart health.

L-Carnitine For Athlete’s Performance

L-carnitine can be taken as a supplement to increase athletic performance, as it not only promotes energy production but it also helps in the preservation of bodies glycogen storage. It prevents the body from using amino acids for energy production by increasing the oxidation of fatty acids. This effect of L-carnitine results not only in increased energy production by preserving the body’s resources but also reduces recovery time by reducing the accumulation of lactate.

In some research studies L-carnitine intake has been shown to increase oxygen utilization in the body and it also increased the VO2 max resulting in better endurance and aerobic capacity.
However, the research on the effects of L-carnitine on athletic performance is not conclusive and might depend on other factors as well, as one systemic analysis, of multiple clinical trials with more than 200 participants shows that in some trials L-carnitine improved VO2max, peak strength, peak sprinting power, exertion, number of leg presses, while in other it showed little to no effects on these parameters.

Still, L-carnitine can help athletes by reducing fat cells, increasing energy production, and reducing oxidative stress caused by high-intensity exercise which also reduces the total recovery time of the athletes.

L-Carnitine For Male & Female Fertility

In the human body L-carnitine is present in almost all cells including testes and ovaries, where it helps in the production of reproductive cells (sperm and ova) in both males and females by reducing the effects of oxidative stress and increasing the production of sex hormones such as testosterone.

In assisted reproductive techniques L-carnitine has been used as adjunctive therapy to increase the chances of a successful pregnancy.

In males, L-carnitine might help in sperm maturation, motility, and production. In a study of several clinical trials, it was shown that supplementation with L-carnitine increased sperm motility and morphology by 7.84% and 4.91% respectively.
In another study, L-carnitine supplementation increased sperm concentration in men.

Sources of L-Carnitine

L-carnitine is naturally present in most animal products and in some plants. Although It is found in higher concentration in animal products it is not hard to get it from plant sources for your daily requirement, here is a list of common sources which contain L-carnitine:

Animal-Based Foods:

  • Beef steak
  • Ground beef
  • Milk: Whole
  • Codfish
  • Chicken breast
  • Ice cream
  • Cheese: cheddar

Plant-Based Foods:

  • Whole-wheat bread
  • Asparagus
  • Tempeh
  • Sesame seeds
  • Pumpkin seeds
  • Tahini (sesame seed paste)
  • Brewer’s yeast
  • Mushrooms (particularly shiitake mushrooms)
  • Corn
  • Buckwheat
  • Artichokes
  • Mustard greens
  • Brussels sprouts
  • Parsley

L-Carnitine Supplements*

  • L-Carnitine L-Tartrate (LCLT)
  • Acetyl-L-Carnitine (ALCAR)
  • Propionyl-L-Carnitine (PLC)
  • Glycine Propionyl-L-Carnitine (GPLC)
  • L-Carnitine Fumarate
  • L-Carnitine Orotate

*Usually available in the form of powder or capsule, and can be taken by mixing it with other supplements or with water.


(How much l-carnitine should I take?)

The human body needs about 15 mg of L-carnitine every day for daily requirements, some of which is produced in the body and some of it is from dietary sources. However, in certain health conditions, one may take L-carnitine in higher doses for its health benefits.

For Cardiovascular Health: 1-6 grams/day
For Fertility: 1- 3 grams/ day
For Weight loss: 2-10 grams/day
For Athletic Performance: 1-4 grams/Day

*It is important to know that there is no scientific consensus on how much L-carnitine to take every day for its health benefits, the dosage given here is compiled from several clinical trials which showed a positive effect for a particular health condition.
*As L-carnitine causes fatty acid oxidation it is better to take it in combination with anti-oxidants such as Alpha-Lipoic Acid.

L-Carnitine Side Effects

L-carnitine has been shown to have several health benefits and in many trials, it has been documented to have no or minimal side effects even in year-long studies. Still, there are some side effects that one might face while using L-carnitine as a supplement:

Gastrointestinal Side Effects:

  • Nausea
  • Vomiting
  • Diarrhea
  • Stomach cramps
  • Heartburn
  • Body Odor

Allergic Reactions:

  • Rash
  • Itching
  • Swelling (face, lips, tongue, throat)
  • Dizziness
  • Difficulty breathing
  • Appetite and Weight Changes:

Additionally, it may also cause a fishy odor in sweat, urine, or breath, increased appetite, weight gain, and disruption of thyroid hormone levels in individuals with hypothyroidism or underactive thyroid.


L-carnitine is a naturally occurring amino acid derivative that plays an essential role in the production of energy by transporting fatty acids to mitochondria. After its discovery and isolation in 1905, it was thought to be a kind of vitamin and named Vitamin BT however it is not a vitamin rather it is an occasional essential nutrient for proper body function.
L-Carnitine is being researched for its several health benefits and some of those include better heart health, fertility, athletic performance, and weight loss. Due to its antioxidant properties, it is also shown to have several other health benefits.
It is present in several food sources and can be easily consumed in the form of dietary supplements as well. However, it is important to know that more research is required to fully understand the health benefits of L-carnitine.