What is carnitine? Carnitine is produced in the body from the amino acid lysine and naturally occurs in some foods. It supports energy metabolism and muscle function, which are important factors in PDF) Comparison of pharmacokinetics of L carnitine, Acetyl L carnitine and Propionyl Lcarnitine after single oral administration of L carnitine in healthy volunteers When Should You Take L Carnitine? MuscleTech Altrient Liposomale Acetyl L Carnitine 1000 mg (30 sachets) L Carnitine 3000 Liquid