Just as the endocrinology specialty’s objections to the use of desiccated thyroid and T3 are based on presumption, so is its long-standing dictum that T4-replacement is always safe and effective. Some members of the specialty have been steadfastly convinced of the fail-safe effectiveness of T4-replacement. When patients complain of continuing hypothyroid symptoms despite using "adequate T4-replacement," these members argue that something other than a thyroid hormone deficiency must be causing their symptoms.

Witness, for example, statements by thyroid surgeon Richard Guttler: "We have the most accurate thyroid testing, and if you test normal, and have symptoms, most likely your symptoms aren’t due to abnormal thyroid balance." And further, "[I] rely on accurate thyroid blood testing. The thyroid tests are abnormal way before [patients] have ‘thyroid related symptoms’. Other similar symptoms, such as fatigue, and weight gain are not thyroid related if the testing is stable and normal."[49] (Italics mine, and incorrect punctuation is Guttler’s.)

Similarly, consider a comment of influential endocrinologist M.I. Surks in a chapter on treating hypothyroidism in the widely used thyroidology textbook, Werner’s The Thyroid: "Notwithstanding the physician’s assurance that the T4 dose is optimal, and the demonstration that serum TSH has decreased into the normal range, these patients may ask for a larger dose or take a larger dose on their own initiative. In this setting, the patient should be reassured that the T4 dose prescribed is appropriate, and other causes of the patient’s complaints must be investigated."[43] (Italics mine.)

Surks’ advice to reassure the patient that his or her dosage "is appropriate" presumes that the patient’s T4 dose is adequate for his or her individual needs. His advice that "other causes of the patient’s complaints" be investigated suggests a preconceived notion that replacement dosages of T4 are infallibly effective. In addition, his advice, like that of Guttler, implies that if a patient has hypothyroid-like symptoms despite using T4-replacement, the symptoms are probably caused by some other disorder.

Endocrinologists can maintain this belief only by ignoring published evidence showing it to be false.[8][68] Consider, for example, a finding of Fraser et al.[68] The study result reveals the harm many hypothyroid patients suffer when their physicians make dose decisions based on TSH levels.

2003 Studies of
Thyroid Hormone Replacement Therapies:
Logical Analysis and Ethical Implications
by Dr. John C. Lowe