Does L Carnitine help manage hyperthyroidism symptoms? Consensus The supplement secret for hyperthyroidism? , When dealing with hyperthyroidism or Graves disease, L carnitine can be a total game changer. It helps block the entry of thyroid hormone into the cell L Carnitine Linus Pauling Institute Oregon State University Graves' Disease Treatments: Options, Effectiveness, and Risks Adding L Carnitine and Selenium to Methimazole in Graves' Disease: A Prospective Randomized Trial on Thyroid Markers and Quality of Life