There has been much attention given to supplements the past few weeks. This research on thyroid supplementation is just another reason to ensure that you are working through a healthcare professional. They found varying levels of actual thyroid hormones in supplements which can be dangerous when unneeded. The use of thyroid hormones in someone with a normal functioning thyroid can actually suppress thyroid function. In addition, many thyroid supplements contain iodine which has been linked to thyroid antibody production–these antibodies start a cascade of destruction of the thyroid gland.