However, a study completed in 1990 — but didn’t appear until 1997 in the Journal of the American Medical Association — looked at the problem again. Twenty women who were receiving successful treatment for hypothyroidism were put on four different preparations at the same dosage for six weeks at a time. Blood tests taken during this study showed absolutely no difference in any of the preparations. All the preparations met the Food and Drug Administration criterion for equivalent activity. The conclusion was that the preparations, including two brand names and two generics, were sufficiently equal in their activity, and that no reason supported choosing any one over the others. I’m happy to add that my great thyroid mentor, Dr. Francis Greenspan, among others, performed this study. Some allege that one of the brand-name companies making thyroid-hormone replacement originally paid for the preceding study, and that when the study didn’t show that its product was better, the company suppressed the study’s results. Generic thyroid preparations save you money, and you can use them interchangeably with brand-name thyroxine. Because hypothyroidism may not be a stable condition, you still want to have your doctor check your thyroid function regularly (perhaps yearly).
I Have to Take Thyroid Medication for Life Doctors tell many patients that once they’re on thyroid-hormone replacement, they must take it for life. For many people, this is true. Any treatment that removes or destroys much of the thyroid (such as surgery or radioactive iodine) requires treatment with thyroxine (T4 hormone) for life. However, in certain situations, hypothyroidism is temporary; you may need thyroxine for a time, but you later stop taking it. Sometimes the fact that you no longer need the medication may be obvious, but other times you and your doctor may need to attempt a trial period off thyroid for four to six weeks to see if you still need it. The following are some of the conditions that require thyroid-hormone replacement for a limited amount of time. I explain each in detail in Chapter 11: Subacute thyroiditis causes the temporary breakdown of thyroid cells and the release of thyroxine from the thyroid. As this condition improves, your thyroid begins to make and store thyroxine again, and oral thyroxine is no longer necessary. Silent and postpartum thyroiditis also cause temporary loss of thyroxine, which the body restores with time. Acute thyroiditis occasionally requires temporary treatment with thyroid hormone.