Metabolites as regulators of insulin sensitivity and metabolism Nature Reviews Molecular Cell Biology Did you know L carnitine, a vital amino acid, is naturally produced by your body and found in various foods? While acetyl L carnitine (ALCAR) can be a beneficial supplement for some, most people get Carnitine supplementation improves metabolic flexibility and skeletal muscle acetylcarnitine formation in volunteers with impaired glucose tolerance: A randomised controlled trial eBioMedicine Frontiers The Effects of L Carnitine, Acetyl L Carnitine, and Propionyl L Carnitine on Body Mass in Type 2 Diabetes Mellitus Patients