L Carnitine has become one of our top 5 sellers the last few years and when you review the research, you can see why. L carnitine is a supplement probably more well known if L Carnitine Injection Levocarnitine IV Carnitine: the claims and why it may not work Muscle Specific Deletion of Carnitine Acetyltransferase Compromises Glucose Tolerance and Metabolic Flexibility ScienceDirect How L Carnitine Supports Insulin Resistance Management Oana Posts Carnitine supplementation improves metabolic flexibility and skeletal muscle acetylcarnitine formation in volunteers with impaired glucose tolerance: A randomised controlled trial eBioMedicine