Is L Carnitine safe for athletes at doses up to 6000 mg day? Consensus 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 Research Breakdown on L Carnitine Examine L Carnitine: Uses, Side Effects, Interactions, Dosage and Supplements L Carnitine for PCOS: Everything You Need to Know PCOS Nutrition Center