Can Acetyl L-Carnitine and Alpha Lipoic Acid Increase Strength and Performance?

Just recently, scientific interest in alpha lipoic acid (ALA) and acetyl L-carnitine (ALC), has exploded and a large number of studies are now under way with human trials. The initial results used on mice looked encouraging, but what are the implications for human use– and can these nutrients be harnessed to improve performance?

The reason for the increase of interest is because of a study done in California that found a significant increase in strength, memory, and energy in older aged mice. In this study the mice were given Acetyl L-Carnitine and Alpha Lapoic Acid to see if it would help increase the amount of energy that is produced from mitochondria.

Carnitine is an amino acid that carries fatty acids into the mitochondria, where they are ‘oxidised’ to help create energy. Acetyl L-carnitine is very similar to the amino acid carnitine. Levels of acetyl L-carnitine tend to decrease after the age of 40.

The main role of acetyl L-carnitine (ALC) is to carry fatty acids from the cytosol a par of the cell into the mitochondria another part of the cell so that these fatty acids can be oxidised for energy. Although L-carnitine carries out this role too, acetyl L-carnitine (ALC) also provides acetyl groups, from which acetyl-coenzyme-A  can be regenerated, thereby facilitating the transport of metabolic energy and boosting mitochondrial activity.

Acetyl L-carnitine (ALC) has a greater solubility in water, which helps it diffuse easily across the inner wall of the mitochondria and into the cell cytosol. This simply means that acetyl L-carnitine can reach parts of the cell and body that L-carnitine cannot and also enhances the action of the mitchondria. Acetyl L-carnitine (ALC) is also involved in the production of the key brain neurotransmitter acetylcholine and is also able to donate its acetyl group in a number of other biochemical reactions. This function explains why some studies have shown an increase in brain function.

Alpha lipoic acid (ALA) is an antioxidant, which occurs naturally, in foods such as spinach, broccoli, beef, yeast, and organs such as the kidney and heart. Alpha lipoic acid (ALA) water soluble and fat soluble, which allows it to exert an antioxidant effect in almost every part of the body, including the brain. In the mitochondria, alpha lipoic acid (ALA) can act both as an antioxidant, capable of recycling other antioxidant nutrients such as vitamin C and vitamin E, and as a coenzyme for key metabolic enzymes involved in energy production. In addition to its role as an antioxidant, alpha lipoic acid (ALA) also raises the levels within cells of a substance called glutathione, which is critical for neural function, and aids in glycolysis, the first stages of breaking down carbohydrates for energy.

As I mentioned earlier an increase interest in Acetyl L-Carnitine and Alpha Lapic Acid started with a team of researcher in California performed a study on elderly rats. A study before hand found that Acetyl L-Carnitine could reverse age related decline in the mitichondrial of rats. The problem was that their was an increase in oxidative damage. To revese this problem the antioxidant Alpha Lipoic Acid was added. They were hoping that they would get both to work with each other to cause an increase in mitochondrial energy production and reduced mitochondrial damage.

The mix of both of these supplements seemed to work and produced the best results that they had seen. After a month of supplementation the rats had more energy and performed better memory tests. The rats being fed the supplementation showed signs of being middle aged rats rather than elderly rats.

Could it Work For Humans?

In a few months that followed the initial study, a number of human studies were started, many of which are still going on today. The problem that these studies face, is that humans live a lot longer than rats and it takes much longer to get proven and sound evidence of the effect of acetyl L-Carnitine and Alpha Lipoic Acid on humans

A double blind, placebo controlled study was done at San Francisco State University on the effects of acetyl L-carnitine and alpha lipoic acid on humans. The study used biomarkers to determine the oxidative stress placed on the human body. The study found that there was a significant decrease in the oxidative stress on the human body for people taking the supplements compared to the people taking the placebo. 

If acetyl L-Carnitine and alpha lipoic acid can really decrease oxidative stress on the human body then this could be a huge benefit for middle aged and elderly people. The results of the test may also be important for athletes who have an increase in exercise induced oxidative stress.

More human studies are under way, but so far there are no published human studies available, although positive studies in animals continue to proliferate. Last year, American researchers demonstrated that alpha lipoic acid (ALA) supplementation in older racehorses reduced the oxidative stress burden even under light training loads, while a number of other animal studies have shown that acetyl L-carnitine (ALC)/ALA supplementation reduces oxidative stress and improves mitochondrial function in a number of tissues, including brain, muscle and heart.

In another study, researchers examined the effects of acetyl L-carnitine (ALC)/alpha lipoic acid (ALA) therapy on ageing and hearing in rats, and found that it reduced the normal age-associated deterioration in auditory sensitivity and improved inner ear function. They concluded that these improvements were related to the acetyl L-carnitine (ALC)/ALA combination’s ability to protect and repair age-induced mitochondrial DNA damage, thereby boosting mitochondrial function and improving energy turnover. However, while the initial evidence from animal studies looks extremely promising, the jury is still out as far as humans are concerned.


As studies continue to poor out it is important to remember to take these studies one at a time. It is important to get all the details from more conclusive studies before jumping to conclusions. Acetyl L-carnitine is a fairly expensive supplement and the cheaper L-Carnitine supplementation has not be used in studies.

One important thing to note with this research is that if the supplementation of acetyl L-Carnitine and Alpha Lipoic acid  help repair and strengthen the Mitochondria then there is a good chance that this supplementation can help increase the average age and energy of humans.


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