Benefits of Acetyl L Carnitine Simply Supplements Does L Carnitine help manage hyperthyroidism symptoms? Consensus L Carnitine vs. CoQ10: Battle of the Super Nutrients! Ultimate Sup Normal labs don't always explain fatigue, weight changes, or feeling off. Thyroid imbalances do not always present in obvious ways. Symptoms can vary depending on whether the thyroid is underactive or overactive, If you are like a lot of people, you may have never heard of carnitine but this important nutrient is critical for our body's ability to optimally burn fat required for energy. Is it safe to take L carnitine with levothyroxine (thyroid medication)?