Combination of selenium and L carnitine normalizes the overactive thyroid gland How Should I Use Thyroid Supplements? How Does Carnitine Support Hashimoto's? Dr. Izabella Wentz L carnitine supplementation for the management of fatigue in patients with hypothyroidism on levothyroxine treatment: a randomized, double blind, placebo controlled trial. Semantic Scholar What are the natural treatment options for Graves' disease (Hyperthyroidism )? 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.