Effects of L-carnitine on obesity, diabetes, and as an ergogenic aid

Asia Pac J Clin Nutr. 2008;17 Suppl 1:306-8.


Data on the functionalities of L-carnitine on obesity, diabetes, and as an ergogenic aid are summarized as follows: Obesity: Total lipid, triglyceride, and total protein increased during the 3T3-L1 cell differentiation. However, nonesterified carnitine (NEC), acid-soluble acylcarnitine (ASAC), and acid-insoluble acylcarnitine (AIAC) concentrations were lower in the differentiated 3T3-L1 cells. In addition, the exogenously added carnitine inhibited the increases in triglyceride and total lipid levels. In an animal study, L-carnitine supplementation reduced serum leptin and abdominal fat weight caused by high-fat diet in C57BL/6J mice. Diabetes: In an animal study, streptozptpcin-induced diabetic rats had markedly lower IGFBP-3 than normal rats, and IGFBP-3 was increased by L-carnitine treatment, demonstrating that L-carnitine treatment of diabetic rats modulates the IGFs/IGFBPs axis. A study of Korean diabetics indicated that there is a remarkable abnormality in lipid and carnitine metabolism in Korean diabetic patients. Ergogenic aids: We investigated the separate and combined effects of L-carnitine and antioxidant supplementation on carnitine and lipid concentrations in trained and non-trained animal and humans. Supplementation of L-carnitine and antioxidants improve lipid profiles and exercise ability in exercise-trained rats. Also, both exercise training and supplementation of carnitine and antioxidants improved lipid profiles and carnitine metabolism in humans, suggesting that carnitine and antioxidant supplementation may improve exercise performance.

Publication types

  • Review

MeSH terms

  • 3T3-L1 Cells
  • Animals
  • Carnitine / pharmacology*
  • Cell Differentiation / drug effects*
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Diabetes Mellitus, Type 2 / metabolism
  • Exercise / physiology*
  • Humans
  • Lipid Metabolism / drug effects*
  • Mice
  • Obesity / drug therapy*
  • Obesity / metabolism


  • Carnitine