Acetyl L Carnitine: Benefits, Forms, Dosing, and Side Effects Dr Brad Stanfield Nanoparticle mediated L carnitine delivery for improved male fertility ScienceDirect Boost Your Burn: How L Carnitine Might Help You Lose Weight Government Polytechnic Mumbai L carnitine is a naturally occurring amino acid structure that is made in the human brain, liver, and kidneys. L carnitine plays a critical role in energy production, as it converts fat into energy.