Acetyl L Carnitine 1500mg, Brain Function, Fat Metabolism, Energy Production Increased peripheral of brain derived neurotrophic factor levels in phenylketonuric patients treated with l carnitine ScienceDirect Acetyl L Carnitine, 500 mg, 100 Vegetable Capsules Enhance Your Performance and Brain Health with Beast Labs Nutrition Ac Supps247 Acetyl L Carnitine vs L Carnitine: 4 Key Differences Momentous 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.