Abstract. Dr. Richard Guttler has been a member of the American Association of Clinical Endocrinologists’ guidelines committee for the diagnosis and treatment of hypothyroidism, and he has proclaimed himself “the real thyroid expert.” In 2004, Guttler published false claims about natural desiccated thyroid (NDT). One of his claims is that NDT has “none of the benefit” that T4 provides patients. In the same document, however, he himself showed that this claim against NDT is false. He did so by citing historical evidence that desiccated thyroid is an effective treatment for hypothyroidism. Later in 2004, I published a rebuttal of Guttler’s false claim about NDT. He didn’t attempt to refute my argument that his claim was false; instead, he kept the false claim online at his website. He subsequently stated that I failed in my rebuttal to use “a single shred of evidence.” This statement, too, is a false claim by Guttler. In this paper, I provide more evidence that his allegation against NDT is false. I believe it is crucial to the health and well-being of many hypothyroid patients that Guttler open-mindedly acknowledge the falsity of his claim that NDT does not provide benefits. Some clinicians may accept without question his false claim and deny patients NDT as a potentially effective alternative when they fail to benefit from T4 replacement.

Keywords. Armour Thyroid • Desiccated thyroid • Nature-Throid • NDT • Richard Guttler • T4 • Westhroid