Does L Carnitine Work for Fat Loss? A Dietitian Explains Diabetes and Glucose Control Life Extension Does L Carnitine Lower Blood Sugar? A Practical Look At The Evidence [jaJCRz00AMQ] 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. L Carnitine: Benefits, Side Effects, And Dosage, Per Dietitians