Acetyl L Carnitine: Benefits, Forms, Dosing, and Side Effects Dr Brad Stanfield Early research into L carnitine was often cited as underwhelming, showing negligible changes in muscle carnitine content and fat loss outcomes. However, these findings may have been limited by a short study window Role of L carnitine in female infertility Reproductive Biology and Endocrinology Springer Nature Link The effect of l carnitine on fat oxidation, protein turnover, and body composition in slightly overweight subjects. Semantic Scholar