L Carnitine For Thyroid Patients L carnitine supplementation for the management of fatigue in patients with hypothyroidism on levothyroxine treatment: a randomized, double blind, placebo controlled trial. Semantic Scholar Comparison of short term and long term effects of peroral L carnitine intake: clinical implications of elevated TMAO levels in cardiovascular complications Role of carnitine in disease Nutrition & Metabolism Springer Nature Link 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. Are these Supplements Hurting your Thyroid?