Do You Need to Cycle Creatine for Optimal Muscle Growth? VPA Australia 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 Revolution Nutrition Carnitine Cooler Powder L Carnitine Tartrate Lean supplement Amino Acid Enhance Endurance Zero Calorie L Carnitine Benefits, Uses, Dosage, Foods, Side Effects Dr. Axe L Carnitine: Benefits, side effects, and dosage