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How to Use L-Carnitine to Boost Performance and Slow Aging

L-Carnitine is an amino acid that is naturally produced by the body and helps turn fat into energy. Not only does it help with weight loss but it also improves heart and brain function, sports performance, and slows aging. In this article, we’ll explore L-carnitine and why you should consider adding it to your longevity toolbox.

What is L-Carnitine?

L-carnitine is a naturally occurring amino acid that’s found within the cells of our body. It plays a vital role in the body’s energy production through the transport of fatty acids into the mitochondria (the powerhouse of the cell). Here these fatty acids are oxidized (burned) to produce energy.

Your body produces L-carnitine from the amino acids lysine and methionine which are found predominantly in animal proteins. However, research has shown that vegans or those suffering from certain genetic disorders may not be able to produce sufficient amounts, making L-carnitine a conditionally essential amino acid.

L-carnitine can be found in the following forms:


It is an inactive form of L-carnitine and should be avoided as it may block other forms of L-carnitine within the body. This can cause symptoms that resemble L-carnitine deficiency.


Often called ALCAR has shown positive effects again neurodegenerative diseases and in the treatment of aging through the slowing of mental deterioration.


Is believed to increase nitric oxide which aids in blood flow making it a suitable choice against circulatory problems and high blood pressure.

L-carnitine L-tartrate

Is often found within sports supplements as it helps prevent muscle soreness, muscle damage, and increases muscle recovery after exercise.

What Does L-Carnitine Do for You?

L-carnitine's main role in the body is to transport fatty acids into the mitochondria to be burned up and used as energy. But recent research has shown other benefits as well, including cardiovascular health.

Due to its important role in energy production as well as being a generally safe supplement, L-carnitine has been extensively studied. Here are some of the benefits and findings.

Helps with weight loss

L-carnitine helps the body burn fat. But, interestingly, there have been a few studies that have varied in their results with regards to L-carnitine and weight loss.

During a study of 38 moderately obese women who exercised 4 times daily for 8 weeks, there was no difference in weight loss between those who supplemented with L-carnitine and those who didn’t. In another study, 4 weeks of supplementing with L-carnitine did not increase the fat burning effect during a 90-minute cycle.

However, upon analysis of nine trials conducted in primarily obese or older individuals, those taking L-carnitine lost an average of 2.9 pounds more weight while supplementing with L-carnitine.

Although further study is needed into the benefits of L-carnitine, studies show that it may aid in weight loss for older adults or obese individuals. It’s also important to mention that results may vary between individuals and that if you do take L-carnitine, it’s best to take it in conjunction with a healthy diet and active lifestyle.

May help prevent muscle loss

L-carnitine helps balance the formation and degradation of proteins in the muscles to fight muscle loss. The loss of muscle tends to occur with age (known as sarcopenia) especially if you have an unhealthy diet and don’t exercise. One study found that L-carnitine suppressed the loss of skeletal muscle in subjects that had liver cirrhosis.

Another study found that L-carnitine helped reduce muscle wasting in a subject undergoing stroke rehabilitation. In this interesting study, the subject was initially given botulinum neurotoxin injections to reduce the spasticity in her right leg so that she could walk. Her walking improved, however, it declined after the second and third treatment because of leg pain during walking and muscle wasting. The researchers then prescribed L-carnitine and she experienced a rapid improvement in pain and her continuous walking distance. When the researchers stopped L-carnitine, the subject did not experience a reoccurrence of pain or muscle loss which indicated that the amino acid helped reduce muscle damage during rehabilitation.

Both of these studies, and numerous others, indicate that L-carnitine shows great therapeutic potential.

May boost athletic performance and endurance

The benefits of L-carnitine on sports performance remains controversial. Several studies have shown benefits over a long time period and othershave shown benefits when administered acutely.

L-carnitine may help to improve exercise recovery, whilst reducing muscular pain after exercise. It has shown to increase oxygen supply to the muscles, whilst delaying fatigue and discomfort through increased blood flow and nitric oxide production. A study has also shown that L-carnitine may increase red blood cell production which is vital for the transport of oxygen throughout the body.

Aids in brain function

Studies have shown that acetyl-L-carnitine helps to improve learning abilities whilst preventing age-related mental decline. Human studies have gone on to show daily supplementation of acetyl-L-carnitine helps reverse the decline of brain function associated with Alzheimer’s and other brain diseases.

Further studies have shown it to improve general brain function in older adults not suffering from Alzheimer’s or similar brain conditions. In a 90-day study, chronic alcoholics who supplemented with 2 grams of acetyl-L-carnitine daily showed improvements in all areas of brain function.

Improves cardiac function

Studies have shown acetyl-L-carnitine to demonstrate the potential to reduce blood pressure and the inflammation process associated with heart disease. Supplementing with 2 grams of acetyl-L-carnitine resulted in nearly a 10-point drop in systolic blood pressure.

L-carnitine has also shown improvements in patients with chronic heart failure and coronary heart disease. A year-long study showed a reduction in heart failure and deaths amongst participants supplementing with L-carnitine.

Reduces the risk of type 2 Diabetes

L-carnitine has been shown to reduce the symptoms and associated risks of type 2 diabetes.

In a study of type 2 diabetic patients, those supplementing with L-carnitine and their medication saw significant reductions in their blood sugar levels.

Improves male infertility

Research has shown the amount of L-carnitine in semen is directly related to sperm count and motility. Studies have shown that 2-3 grams of L-carnitine daily for 3-4 months may improve sperm quality. A double-blinded crossover trial done in 100 men, found that supplementation with 2 grams of L-carnitine daily for 2 months improved both the concentration and forward motility of their sperm.

May slow mitochondrial decay due to aging

The aging process is thought to be accompanied by a decrease in our mitochondrial function. Recent research has shown that acetyl-L-carnitine supplemented with alpha-lipoic-acid( ALA) may reduce mitochondrial decay.

Alpha-lipoic acid is a naturally occurring fatty acid that also plays an important role in energy production. To find out more, read The Anti-Aging Benefits of Alpha Lipoic Acid (ALA).

What Foods Contain L-Carnitine?

L-Carnitine can be obtained primarily from animal sources like meat, fish, poultry, and milk. Dairy products contain most of their L-carnitine primarily in their whey fraction. For red meat, usually the redder the meat the higher its L-carnitine content. Because this amino acid is found in animal proteins, vegans and strict vegetarians need to consider supplementation.

Below is a list of food that contains the highest sources of L-carnitine:

  • Beef: 81mg per 3oz (85g)
  • Pork: 24mg per 3oz (85g)
  • Fish: 5mg per 3oz (85g)
  • Chicken: 3mg per 3oz (85g)
  • Milk: 8mg per 8oz (227ml)

Why Take L-Carnitine as a Supplement?

Your need for L-carnitine is directly influenced by how much your body produces and how much you consume. And, although we can obtain it from animal sources, it’s difficult to determine exactly how much you are getting in. Also, if you are vegan or a strict vegetarian, supplementing with L-carnitine is essential.

As with many other molecules in our body, research shows that our L-carnitine levels decrease with age. Studies have shown that 2 grams of L-carnitine a day is a great way for older individuals to increase muscle function, reduce fatigue, and boost brain health.

What’s the best L-carnitine supplement?

Unfortunately, when taken as a traditional supplement, the bioavailability of L-carnitine is very low. To maximize absorption, L-carnitine is usually injected. However, thanks to cutting-edge technology, you can now take L-carnitine in a liposomal form which improves bioavailability and makes it easier for your body to absorb without the inconvenience of injections. Youth & Earth has a liposomal carnitinesupplement specifically designed for maximum absorption.

To find out more about why the liposomal form of supplements is so effective, you might like to read: What are Liposomal Supplements and How Do They Work?

When Should I Take L-Carnitine?

Because L-carnitine is rapidly absorbed by the body, it is best suggested to take it early in the morning and/or before exercise. However, it is important to note that it can be taken any time during the day and will not disturb your sleep if you take it at night.

Does L-Carnitine Have Any Side Effects?

For most people, L-carnitine is generally safe. However, mild side effects may include nausea, vomiting, and stomach discomfort. It can also cause the body, urine, and sweat to produce what is described as a “fishy” odor. In rare cases, muscle weakness and seizure have been noted. It’s always best to consult with a healthcare practitioner before starting any supplement regime.

L-carnitine supplements have also been shown to raise your trimethylamine-N-oxide (TMAO) levels over time. With TMAO being directly linked to atherosclerosis (a disease which clogs the arteries). While TMAO is a notable side effect, it is mainly visible in chronic amounts of L-carnitine supplementation. Research gathered in this human study suggests large amounts of L-carnitine (6 grams daily) is required for significant increases in TMAO.

A human studyhas shown no change in the increase of plasma TMAO in dosages of 0,5g, 1g, and dosages of L-Carnitine administer three times daily. One study has even shown taking 3 grams of L-carnitine daily for 21 days to have no negative side effects on healthy users. If you are supplementing with L-Carnitine, we would recommend keeping your daily intake below 2 grams daily and following the recommended dosage.


L-carnitine is an amino acid found within the muscles of our body that functions to produce energy through the oxidation of fatty acids. Although mainly marketed towards weight loss and sports performance, L-carnitine shows a wide range of health benefits and is generally safe when taken in moderation.

It is a great way to improve your energy levels, fight off mental fatigue, and increase your concentration by improving your ability to learn. Studies have shown benefits in those with lower levels and it should be a serious consideration for older adults, vegans, and vegetarians.

We all desire to enjoy our lives as we grow older, so why not fight the signs of aging, improve your brain function, and increase your energy levels by supplementing with L-carnitine daily.

Life is not merely being alive, but being well.

— Marcus Valerius Martialis

The content of this article is for informational purposes only. It’s not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or health provider before starting a new health regime or program. Do not ignore medical advice or delay seeking it because of something you’ve read on this site or any Youth & Earth product.