L Carnitine Side Effects & Risks The effect of l carnitine supplementation on mortality and clinical outcomes in ventilator dependent critically ill patients with obesity and COVID 19: Protocol for a randomized double blind placebo controlled trial ScienceDirect 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 Acetyl L Carnitine (ALCAR) Supplement for Horses Mad Barn What are the symptoms of carnitine (L carnitine) deficiency?