Maximum L Carnitine Alfa Vitamins Alfa Vitamins Store Liquid L Carnitine Citrus Swanson Vitamins L Carnitine Fumarate with Biosint Carnitine, 60 Veggie Caps (500 mg per Veggie Cap) L Carnitine Advanced Orthomolecular Research Inc. Canada 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