Most people talk about carnitine like it is one supplement. It is not. Acetyl L carnitine and L carnitine L tartrate do different jobs, and picking the wrong one for the wrong goal is where people Carnitine: the claims and why it may not work Levocarnitine Tablets (330 mg) Levocarnitine Oral Solution (1 g 10 mL multiple unit container) Levocarnitine Oral Solution (Sugar Free) (1 g 10 mL multiple unit container) For oral use only. Not for parenteral use. The adverse effects of long term l carnitine supplementation on liver and kidney function in rats L Liu, D M Zhang, M X Wang, C Y Fan, F Zhou, S J Wang, L D Kong, 2015 Is Diarrhea a Possible Side Effect of Taking Creatine?