L-carnitine is an important molecule because it’s needed to convert fat into energy. The name carnitine is derived from Latin “carnus” (flesh), because it was originally found in meat extracts. Animal products such as meat, poultry, fish, and milk are the best food sources, with redder meats tending to have higher levels of L-carnitine. Adults eating animal products consume about 60–180 milligrams of carnitine per day. The human body can make carnitine from lysine using other micronutrients as cofactors. Adults eating a variety of animal products get about 75% of the daily carnitine needs filled from the diet, so only need to make about 25% of what they use. Vegans get noticeably less (about 10–12 milligrams), with vegetarians getting a bit more than vegans because of eating dairy products. In both cases, because the diet is limited in L-carnitine, they may need to make as much as 90% of their daily needs. While the human body can make carnitine from lysine, it may not always be able to make sufficient amounts to meet demands. This has led to it being thought of as a “conditionally essential” nutrient. L-carnitine’s most important role is in mitochondrial fat metabolism—it is used to transport long-chain fatty acids across the mitochondrial membrane for breakdown by mitochondrial β-oxidation. This transportation function allows fats and oils from our diet to be used for energy production and enhances mitochondria potential to burn fat. This function is especially important in tissues and organs that use a lot of fat as an energy source, including the heart and skeletal muscles.
L-Carnitine is used by the body to transport long-chain fatty acids (fats) so they can be broken down and used to make cellular energy (ATP).
In general, L-carnitine is additive with other strategies used for supporting mitochondrial function (i.e., mitochondrial nutrients like CoQ10 and lipoic acid).
Carnitine can also be supplemented as acetyl-L-carnitine (ALCAR). While both ALCAR and L-carnitine support the same functions, in general, the ALCAR form tends to be used in research more for brain and nervous system support, while the L-carnitine form has been researched more for supporting heart and skeletal muscles. But both forms support all tissues.
L-carnitine sourcing is focused on ensuring it is NON-GMO, gluten-free and vegan.
L-carnitine is generally considered to be dose-dependent (see Neurohacker Dosing Principles) in the range it’s commonly dosed (between 500 mg to several grams a day). These higher supplemental doses are pharmacological (i.e., substantially higher than what the body gets from the diet and makes daily), while a lower dose would be more physiological. We opted for a dose slightly higher than the daily physiological amount, because, like most nutrients, L-carnitine isn’t perfectly absorbed.
Mitochondrial function and structure
Healthy aging and protective effects
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