L-Carnitine 600mg/ml (20mL)

L-carnitine carries long-chain fatty acids into mitochondria, where they are burned for energy. It is abundant in red meat.

• Carnitine deficiency (the approved use)
• Outcomes after heart attack (meta-analysis)
• Gut-microbe conversion to TMAO and atherosclerosis

It is a carrier molecule that moves long-chain fatty acids across the inner mitochondrial membrane for oxidation - the main energy source of heart and skeletal muscle.

1. Approved drug

   FDA approval (Carnitor, 1985)

   Levocarnitine was approved on December 27, 1985 (NDA 018948). The label lists primary systemic carnitine deficiency and secondary carnitine deficiency from inborn errors of metabolism.[1]

2. Review

   After heart attack: meta-analysis (Mayo Clin Proc 2013)

   13 controlled trials with 3,629 patients after acute myocardial infarction. L-carnitine was associated with 27% lower all-cause mortality, 65% fewer ventricular arrhythmias and 40% less angina, with no reduction in heart failure or repeat heart attack. The authors call for large randomized trials in the modern era.[2]

3. Animal study

   TMAO and atherosclerosis (Nat Med 2013)

   Gut bacteria convert dietary L-carnitine into TMAO. Long-term L-carnitine supplementation increased atherosclerosis in mice unless their gut bacteria were suppressed, and omnivores made more TMAO from L-carnitine than vegans or vegetarians.[3]

4. Human · small / uncontrolled

   The human gut pathway (J Clin Invest 2019)

   Tracer studies in omnivores and vegans or vegetarians: omnivores produced more than 20 times as much TMAO from labelled L-carnitine, and chronic L-carnitine supplementation switched on the gut-microbe step that makes TMA.[4]

• The heart-attack meta-analysis authors ask for large modern randomized trials to confirm it.
• Mouse and human tracer studies link supplemental L-carnitine to TMAO, a metabolite the authors associate with atherosclerosis.
• Products on this site are sold for laboratory research only. They are not the medicines used in the trials above, and those results do not apply to research material.

1. 1.Carnitor (levocarnitine) tablets and oral solution - original approval December 27, 1985U.S. FDA, Drugs@FDA: NDA 018948 Approved drug
2. 2.L-carnitine in the secondary prevention of cardiovascular disease: systematic review and meta-analysisDiNicolantonio JJ et al. Mayo Clin Proc. 2013 Review
3. 3.Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosisKoeth RA et al. Nat Med. 2013 Animal study
4. 4.l-Carnitine in omnivorous diets induces an atherogenic gut microbial pathway in humansKoeth RA et al. J Clin Invest. 2019 Human · small / uncontrolled