L Carnitine Benefits, Uses, Dosage, Foods, Side Effects Dr. Axe Did you know L carnitine, a vital amino acid, is naturally produced by your body and found in various foods? While acetyl L carnitine (ALCAR) can be a beneficial supplement for some, most people get L carnitine supplementation for the management of fatigue in patients with hypothyroidism on levothyroxine treatment: a randomized, double blind, placebo controlled trial. Semantic Scholar 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. Carnitine vs Acetyl Carnitine: What Quality Differences Do They Have? Hyperpolarized [1 13C]Acetyl l Carnitine Probes Tricarboxylic Acid Cycle Activity In Vivo ACS Sensors