Carnitine supplementation associated with improvement of metabolic syndrome


November 17, 2020

A review and meta-analysis of randomized, placebo-controlled trials published on September 12, 2020 in the journal Nutrients found improvement in factors that characterize metabolic syndrome (MetSyn) among men and women given L-carnitine supplements.

Metabolic syndrome is determined by the presence of three or more factors that include high blood pressure, elevated fasting triglycerides, low levels of high density lipoprotein (HDL) cholesterol, increased abdominal circumference and high fasting blood glucose. The presence of metabolic syndrome is associated with an increased risk of developing type 2 diabetes and cardiovascular disease.

“This study is the first to investigate the effect of L-carnitine supplementation on the biomarkers of MetSyn,” authors Munji Choi of Sungshin Women’s University and colleagues announced.

Dr Choi and associates selected nine articles that reported the findings of trials that evaluated the effects of L-carnitine supplementation among 508 participants and reported data concerning fasting blood glucose, triglycerides, waist circumference, blood pressure or HDL cholesterol. L-carnitine doses ranged from 0.75 milligrams (mg) to 3 grams per day.

Supplementing with L-carnitine was associated with significant reductions in waist circumference and systolic blood pressure in comparison with the placebo groups. When studies that tested doses of 1 to 3 grams were analyzed, L-carnitine was additionally associated with a significant decrease in fasting blood glucose and triglycerides and an increase in beneficial HDL cholesterol. “Ultimately, 2–3 g/day of supplemented L-carnitine is recommended,” the authors remarked.

“L-carnitine supplementation is correlated with a significant reduction in waist circumference and blood pressure,” they concluded. “Additionally, L-carnitine supplementation at a dose of 1–3 gram/day could improve MetSyn by reducing fasting blood sugar and triglycerides and increasing HDL cholesterol.”


Apply What You’ve Learned: Carnitine

  • Carnitine is a dipeptide produced from the amino acids lysine and methionine and is found in most cells of the body.1
  • Like many amino acids, carnitine exists in D (right-handed) and L (left-handed) forms, but it is the L form of carnitine that plays a role in nutrition.
  • Carnitine transports fatty acids into the mitochondria of the cells, which enables mitochondria to break them down to produce energy.2
  • L-carnitine, acetyl-L-carnitine, and propionyl-L-carnitine are available as dietary supplements.


  1. Carnitine, Fact Sheet for Health Professionals. National Institutes of Health. Office of Dietary Supplements. Updated October 10, 2017.
  2. Pekala J et al. Curr Drug Metab. 2011 Sep;12(7):667-78.

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