L Carnitine Early research into L carnitine was often cited as underwhelming, showing negligible changes in muscle carnitine content and fat loss outcomes. However, these findings may have been limited by a short study window Systemic regulation of L carnitine in nutritional metabolism in zebrafish, Danio rerio Scientific Reports L carnitine Could Be Beneficial in Nonalcoholic Fatty Liver Disease Patients by Improving Choline Metabolism and Reducing Liver Biomarkers European Medical Journal