L-Carnitine for Weight Loss Results – Why It DOESN’T Work for Everyone

Use of an L-Carnitine supplement for weight loss may have benefits, but it does not work as well as other diet pill ingredients.

L-Carnitine is an amino acid that is found naturally in meat products and can be synthesized in the body.

It plays a role in energy production and fat metabolism in the body by helping transport long-chain fatty acids into cells where they can be burned for fuel. Not having enough L-Carnitine could interfere with fat burning and metabolic function.

Use of dietary supplements with this ingredient is purported to promote weight loss, but it may not work equally well for all people. It has been shown to reduce fat mass in elderly people, but not in healthy adults.

It may support higher energy levels, better blood glucose regulation and improved exercise performance on some measures. These factors can contribute to healthy weight loss goals as part of a diet program, but this supplement does not appear to significantly reduce body weight on its own.

Those who want to use L-carnitine for weight loss should learn about the potential benefits it offers, as well as the possible risks associated with it. In this article, we will review how the supplement works as well as user experiences with it for fat loss.

L-Carnitine

Amino Acid

Metabolism

Energy

Fitness

How It Works:

• Transports fatty acids into mitochondria
• Involved in energy metabolism
• Anti-aging & exercise benefits

Dosage:

1 - 3 g per day

Safety:

Rated Likely Safe

Top L-Carnitine Products* ❯

View User Ratings* ❯

L-Carnitine for Weight Loss

L-Carnitine (L-3-hydroxytrimethylamminobutanoate) is an amino acid formed from lysine and methionine.

It has been associated with lipid metabolism as well as improved blood sugar regulation and athletic performance.

L-carnitine is involved in the transportation of long-chain fatty acids to the mitochondria inside cells. Energy is produced in the mitochondria by burning fats that are stored in the cell.

Not having enough carnitines in the body can interfere with normal metabolic function and can result in muscle weakness, fatigue and poor mood.

Most people have adequate amounts of this non-essential amino acid in their body. The liver and kidneys make this substance endogenously and it can be obtained from certain dietary sources, such as red meat, dairy products, fish and poultry.

Carnitine is found in different parts of the body, but higher amounts of it are concentrated in skeletal and cardiac tissue, according to the Office of Dietary Supplements. [1]

There are five different forms of this amino acid that appear in dietary supplements:

• L-Carnitine
• Acetyl-L-carnitine (ALCAR)
• L-Carnitine L-Tartrate (LCLT)
• Propionyl-L-Carnitine
• Glycine Propionyl-L-Carnitine (GPLC)

How It Works

Taking L-carnitine supplements is thought to lead to higher energy levels and a higher rate of fat burning, resulting in weight loss. However, this might not be the case in people who are not deficient in this amino acid.

L-carnitine is involved in transporting fatty acids into mitochondria, which allows for energy production and the burning of stored fats. The mitochondria are organelles within your cells that are responsible for producing energy from food you eat.

They convert sugar, fat and protein molecules into adenosine triphosphate (ATP) – the molecule your body uses as a source of energy.

This process is known as fat oxidation, whereby lipid molecules go through the TCA Cycle (tricarboxylic acid cycle or the Krebs cycle) – a series of chemical reactions that occur in your cells to release stored energy from fats, carbohydrates and proteins.

Carnitine also removes harmful compounds from mitochondria, which decreases the risk of having these compounds build up and damage cells. It has also been shown to increase mitochondrial protein count which means it may help your cells produce more ATP.

If you do not have enough carnitine in the body, fat oxidation could be impaired. Use of a supplement in these cases could theoretically lead to a higher rate of fat metabolism and support weight loss.

However, in research studies, taking an oral L-Carnitine supplement has not been shown to increase fat oxidation in normal populations. It has been shown to slightly increase fat oxidation following exercise, but the result was not significant.

Weight Loss Results

Does L-carnitine work for weight loss? While this amino acid plays a role in the production of energy and the reduction of fat, research studies have not shown that supplementation can increase fat loss.

A 2002 study published in the Annals of Nutrition and Metabolism showed that rats had increased fat metabolism when given L-carnitine, but they were in an energy-deficient state. These results have not been replicated in studies on healthy or overweight rats. [3]

Those who are likely to experience a deficiency in carnitine, such as those with a disorder that affects carnitine absorption or individuals on a vegan or vegetarian diet, might benefit from the fat loss effects of supplements, but more research is needed.

A 2000 study in the International Journal of Sport Nutrition and Exercise Metabolism showed that L-carnitine use did not have a significant effect on fat loss in moderately obese women when combined with aerobic training. [4]

Despite these negative results, if you read user reviews for this supplement on sites like Amazon you will typically find people who say that it did help them lose weight. L-carnitine weight loss reviews provided by consumers who use these products indicate that many have experienced loss of belly fat, increased energy and total weight reduction with this supplement.

However, as a fat burner this supplement is typically used with other ingredients that may be promoting the fat loss effects. In testimonials posted online, those who state that L-carnitine is effective for weight loss also typically eat healthy and get regular exercise.

ALCAR for Fat Loss

Acetyl-L-carnitine (Acylcarnitine) is an acetylated version of L-carnitine that also exists naturally in the body. This supplement shares many of the same effects but appears to have a wider range of therapeutic targets.

ALCAR differs from L-carnitine in that it can cross the blood-brain barrier and increase energy production in brain cells, according to a 2003 study published in Biopharmaceutics and Drug Disposition. [2]

It is thought to potentially lead to improved cognition. Some research suggests that ALCAR also has central nervous system stimulant effects but is less powerful compared to caffeine.

L-carnitine is unable to cross this barrier and does not influence energy production in brain cells.

ALCAR has been shown to decrease fatigue and is being investigated for its clinical role in the treatment of chronic fatigue syndrome. Low ALCAR levels are a biomarker for fatigue.

Some athletes and bodybuilders have used ALCAR to promote weight loss, however there are no research studies available to evaluate its efficacy. Human studies are required to determine whether it works.

Risks of Side Effects

L-carnitine products are considered safe for most individuals to take. Using this supplement in excessive dosages could lead to adverse effects.

If taken for weight loss, the suggested dosage is between 1,000 mg to 5,000 mg. The recommended dosage that individuals should take for weight loss varies based on age, health and other factors. Consumers should ask their doctor for a safe dosage and avoid taking larger doses.

Taking large amounts, such as 5 grams per day, might raise the risk of diarrhea, according to the University of Maryland Medical Center. [5] Possible side effects that can occur in rare cases include skin rash, a fish-like body odor and increased appetite.

L-carnitine products should not be taken with D-carnitine due to the potential for interactions. D-carnitine may interfere with some of the effects of the levorotary form.

Those who take certain medications, such as blood thinners, thyroid hormones, valproic acid and doxorubicin, should not take L-carnitine products for weight loss without talking to their doctor first.

Pregnant women should not take this supplement due to a lack of evidence on the safety of these supplements for women in this condition. These supplements are possibly safe for lactating women, according to the Natural Medicines Comprehensive Database. [6]

Those with underlying medical conditions should not take L-carnitine for weight loss without talking to their doctor. Some of the conditions that might be affected by use of this supplement include high blood pressure, diabetes, cirrhosis, kidney disease, peripheral vascular disease and seizures.

Rate This Article

(3 votes, average: 4.00 out of 5, rated)