T3 vs. T4 ReplacementMost endocrinologists doggedly follow practice guidelines from the American Association of Clinical Endocrinologists. As many patients have told us, their endocrinologist switched them to T4 only replacement and they became ill and dysfunctional again. These reports are consistent with studies that show the ineffectiveness and potential harm of T4 alone replacement.

The studies show that T4 only replacement leaves many patients suffering chronically from hypothyroid symptoms [1][2][3][4][5][6][7] and gaining weight they can’t lose through dieting and exercise.[8] The patients are also likely to be prescribed additional medications to take care of side-effects and mistreated symptoms, which can lead to the development of one or more potentially-fatal diseases.[9]

Potential harm from T4 only replacement has been documented in studies and reports to some of the most reputable scientific and medical journals. In view of the risks, you must consider for yourself whether to allow your therapy to be changed from a T3+T4 combination treatment to a T4 alone treatment. If you decide not to permit it, there are doctors who know the risks and will not let you continue to suffer this mistreatment. A doctor who understands how ineffective and harmful T4 alone replacement is for patients.

Some doctors provide individualized care, and are willing to listen to their patients and take the time to find how to treat them, rather than blindly treat them as if a medical guideline is some kind of perfect law written by an all knowing entity.

One needs only look at the history of the practice guidelines to find they are refined when there is an overwhelming amount of evidence that there is a better solution. Bleeding people, lobotomies, electroshock therapy were all widely prescribed practice guidelines at one point. More recently, we have an ever expanding list of medications withdrawn from the market each year, a trend that increased dramatically in the last two decades. Brand names like Fen-Phen, Propagest, Vioxx, Levaquin, Chantix, Prempro, and many others have made the news after overwhelming evidence finally caused them to fall from widely prescribed guideline standards to the focus of public outcry and lawsuits.

From this standpoint, it is hard to understand how doctors not prescribing medications with mounting evidence against them are dismissed as “alternative”. Many of these “alternative” medications have long-term evidence of their efficacy and low risk of side effects. In fact, they all have the stamp of approval from the FDA to treat what they are symptoms/disease/disorder for which they have been prescribed. Armour Thyroid, for instance, was the first thyroid medication.

The original patent predates the FDA. Until recently, the FDA listed it as GRAS (Generally Recognized As Safe), a designation with more stringent requirements than a new medication goes through. It was only when it was discovered that taking an extremely high dose could worsen heart problems that it was downgraded to a medication like everything else on the market.

What “alternative” medications have one in common is they are available in generic brands. What is revolutionary about them is not that they are some brand new medication. Rather, they is a well refined, heavily researched, better understanding of how best to treat the disorders/diseases/symptoms. The medical community simply knows more about medicine than we did even a year ago. There are many instances when something as simple as knowing when to or how to take a medication is more revolutionary than a new medication to treat the same problem.

Armed with not only the research available, but the knowledge of the issue at hand, you should be able to determine who will help you ferret out and correct the cause of your symptoms.


  1. Walsh, J.P., Shiels, L., Mun Lim, E.E., et al.: Combined thyroxine/liothyronine treatment does not improve well-being, quality of life, or cognitive function compared to thyroxine alone: a randomized controlled trial in patients with primary hypothyroidism. J. Clin. Endocrinol. Metab., 88(10):4543-4550, 2003.
  2. Sawka, A.M., Gerstein, H.C., Marriott, M.J., et al.: Does a combination regimen of thyroxine (T4) and 3,5,3′-triiodothyronine improve depressive symptoms better than T4 alone in patients with hypothyroidism? Results of a double-blind, randomized, controlled trial. J. Clin. Endocrinol. Metab., 88(10):4551-4555, 2003.
  3. Clyde, P.W., Harari, A.E., Getka, E.J., and Shakir, K.M.M.: Combined levothyroxine plus liothyronine compared with levothyroxine alone in primary hypothyroidism: a randomized controlled trial. J.A.M.A., 290:2952-2958, 2003.
  4. Cassio, A., Cacciari, E., Cicgnani, A., et al.: Treatment of congenital hypothyroidism: thyroxine alone or thyroxine plus triiodothyronine? Pediatrics, 111(5):1055-1060, 2003.
  5. Bunevicius, R., Kazanavicius, G., Zalinkevicius, R., and Prange, A.J. Jr.: Effects of thyroxine as compared with thyroxine plus triiodothyronine in patients with hypothyroidism. N. Engl. J. Med., 11:340(6):424-429, 1999.
  6. Bunevicius, R. and Prange, A.J.: Mental improvement after replacement therapy with thyroxine plus triiodothyronine: relationship to cause of hypothyroidism. Int. J. Neuropsychopharmacol., 3(2):167-174, 2000 (June).
  7. Bunevicius, R., Jakubonien, N., Jurkevicius, R., Cernicat, J., Lasas, L., and Prange, A.J. Jr.: Thyroxine vs thyroxine plus triiodothyronine in treatment of hypothyroidism after thyroidectomy for Graves’ disease. Endocrine, 18(2):129-133, 2002.
  8. Tigas, S., Idiculla, J., Beckett, G., and Toft, A.: Is excessive weight gain after ablative treatment of hyperthyroidism due to inadequate thyroid hormone therapy? Thyroid, 10(12):1107-1111, 2000.
  9. Saravanan, P., Chau, W.F., Roberts, N., et al.: Psychological well-being in patients on ‘adequate’ doses of L-thyroxine: results of a large, controlled community-based questionnaire study. Clin. Endocrinol. (Oxf.), 57(5):577-585, 2002.