Carnitine vs Acetyl Carnitine: What is the Big Difference?

By: Michael Lam, MD, MPH


What is the difference between carnitine vs acetyl carnitine?Q: What is the difference between Carnitine vs acetyl Carnitine?

Your LAF Prevention Protocol calls for dietary supplementation with L-Carnitine, and Alpha Lipoic Acid, along with CoQ10, Magnesium and Hawthorne, to help enhance the mitochondria function. Elsewhere on the internet I have read about research into the efficacy of Acetyl L-Carnitine and R-Lipoic Acid in enhancing the mitochondria function in rats, resulting in old rats performing like much younger rats. The articles make a point that R- Lipoic acid is used, and not S-Lipoic Acid. This seems to suggest that it would be better to supplement with Acetyl L-Carnitine and R-Lipoic acid, rather than just L-Carnitine and Alpha Lipoic Acid.

Also, the instructions on the container of the L-Carnitine I have been taking say to take it on an empty stomach. However, I find that on an empty stomach the 500 mg tablet causes some stomach discomfort which at times has actually precipitated Atrial Fibrillation, so I have been taking it with meals. Last week at the supplement store I saw a container of 500 mg Acetyl L-Carnitine capsules which had no instructions as to when to take it, which I assume means that it is just as effective with meals as on an empty stomach.

So, my questions are: What is the difference between Carnitine vs acetyl Carnitine? Is Acetyl L-Carnitine more effective? How much is the effectiveness of L-Carnitine degraded if one takes it with food rather than on an empty stomach? What is the difference between Alpha Lipoic Acid, R- Lipoic Acid and S-Lipoic Acid? Is R-Lipoic Acid more effective? Where can one purchase R-Lipoic Acid? (I haven’t seen it on the shelves.)

Carnitine vs Acetyl Carnitine

A: Excellent question, reflecting your in-depth knowledge of supplements: Here are my views: Approximately 7.5% – 10.2% of the body’s total Carnitine content is in the form of ALC. Acetyl-L-Carnitine is the acetylated form of Carnitine that is regarded by some (but not all) experts as particularly beneficial for Brain and Mental Function enhancement. L-Carnitine is the main form of Carnitine synthesized within the human body. It is 100% pure Carnitine and is a common form of Carnitine supplementation. It improves cardiovascular functions and athletic performance.


While the debate on carnitine vs acetyl carnitine continues, my personal feeling is that the difference is quite marginal. Some acknowledged leaders of the life extension movement are presently taking half of their daily ALC dose in the form of L-Carnitine and the other half of their dose in the form of ALC until this debate is settled. R-Lipoic Acid is also a type of alpha-lipoic acid. It has been shown only the R-form is used by mitochondrial alpha-keto acid dehydrogenases. There is evidence that (R)-lipoic acid supplementation may be more potent than either the alpha-lipoic acid sold commercially or S-Lipoic acid. Addition of R-lipoic acid increases ATP synthesis and aortic blood flow during reoxygenation after hypoxia while S-lipoic acid had no effect on ATP synthesis and improved blood flow at only 10-fold the effective dose of R-lipoic. R-Lipoic increased glucose uptake and the number of glucose transporters in muscle tissue much more effectively than s-lipoic. Alpha lipoic acid has been used as a therapeutic agent in humans, esp. for diabetes as well as certain toxicological and pathological conditions of the liver. However, little is known whether r-lipoic can be as effective therapy for certain diseases in human, especially the long term effect. For LAF purposes we want to focus on the mitochondria. For this reason, it is better to use L-Carnitine because that’s where it is concentrated. People with heart disease normally are deficient in L-Carnitine also. Alpha lipoic acid has been studied and proven to be a universal antioxidant. And it works well in both the mitochondrial as well as the serum. I would recommend not isolating to one or two supplements but a whole host of supplements. Supplements are best taken in cocktail form for best effects.

Carnitine and lipoic acid are beneficial for many processes in the body, when one is affected, all are affected. For example, when the mitochondria health is improved, cellular function is improved, which helps rid the body of toxins and cleanse the extracellular matrix. These functions are all part of the NEM, neuroendocrine metabolic response. This response model is a holistic approach to the body, and an understanding that illustrates when one system is functioning well, it helps all systems function well. Alternatively, if one system is strained, there is a cascade that affects all systems in the body. Supplements should work together to help many systems in the body.

I specialized in personalized supplements for people; they are compounded to your need. I don’t foresee any problems in taking L-Carnitine with or after a meal. In fact a lot of the nutrients found in regular food enhance the function of L-Carnitine.


Carnitine vs acetyl carnitine: Find out what the differences are.