Oral administration of l-carnitine improves the clinical outcome of fertility in patients with IVF treatment

Gynecol Endocrinol. 2018 Aug;34(8):684-688. doi: 10.1080/09513590.2018.1431769. Epub 2018 Jan 29.


Age-dependent decline of mitochondrial function has been proposed to be a main cause of decline of embryo quality. Then, l-carnitine plays important roles in reducing the membranous toxicity of free-fatty acids by forming acyl-carnitine and promoting β-oxidation, preventing cell damage. Recent research revealed that l-carnitine played important roles in vitro in oocyte growth, oocyte maturation and embryo development. However, such beneficial effects of l-carnitine in vivo have yet to be verified. The effect of oral l-carnitine supplementation on embryo quality and implantation potential was examined. A total of 214 patients were included in this study. They all previously received in vitro fertilization-embryo transfer (IVF-ET) and failed to conceive. Then they were administered l-carnitine for 82 days on average and underwent IVF-ET again. There were no significant differences in the total number of retrieved oocytes, and their maturation and fertilization rates between before and after l-carnitine administration. The quality of embryos on Days 3 and 5 after insemination was improved following l-carnitine administration (p < .05) in cycles after l-carnitine administration compared with previous cycles. Healthy neonates were born after IVF-ET following l-carnitine administration. Our data suggested that oral administration of l-carnitine to fertility patients improved the developmental competence of their oocytes after insemination.

Keywords: Fertility treatment; free-fatty acids; mitochondria.

Publication types

  • Clinical Trial

MeSH terms

  • Administration, Oral
  • Adult
  • Carnitine / pharmacology
  • Carnitine / therapeutic use*
  • Embryonic Development / drug effects*
  • Female
  • Fertilization in Vitro / statistics & numerical data*
  • Humans
  • Infertility, Female / drug therapy*
  • Treatment Failure


  • Carnitine