Trials of T3, desiccated thyroid and thyroxine in 1958

Here’s my review of this treasure, an article about T3 therapy from the scientific literature in the 1950s…

TITLE: “TRIIODOTHYRONINE—Clinical Effects in Patients with Suboptimal Response to Other Thyroid Preparations” —


Therapies-LT4-LT3-NDTIn this article, “Thirty patients with evidence of hypometabolism or a clinically related condition were given triiodothyronine after suboptimal response to thyroxin or desiccated thyroid.”

In other words, these were patients who had low metabolism (heart rate, body temp) OR a clinically related condition such as a diagnosis of hypothyroidism. They didn’t respond well to T4 therapy (synthroid / levothyroxine) or to desiccated (NDT / DTE), so they then tried treating them with T3.


A few comments on its methods.

This study was conducted over many YEARS as people moved between therapies, so this is no short term trial.

They tried 2 types of T3.

  1. The standard at that time was Cytomel.
  2. Another isomer of T3 was available at the time: a drug marketed as Trionine contained a T3 molecule (DL-T3) that is about 1/2 as potent as Cytomel, so it has to be taken in higher doses to achieve the same effect.

In this era, there was a lot of scientific and medical interest in comparing synthetic T3 and T4 medications with the standard treatment used in therapy to date, desiccated thyroid, which was just called “Thyroid” for short.

In the 1950s, Synthroid / levothyroxine was not commonly in use, but this study examined a few patients who combined it with T3.

They also tried combinations of desiccated thyroid with T3.


A conclusion, from the abstract, was that thyroid therapy is highly individual and there is no way to predict a patient’s response to a particular thyroid therapy modality.

Therefore, why prevent any patient from trying any form of therapy if it might benefit them?

In their words: because “occasional improvement, sometimes dramatic, suggested that a therapeutic trial with triiodothyronine in difficult or unresponsive cases of hypometabolism or hypothyroidism is justified.”

Just try it!

And nobody was harmed.

Details of individuals on therapy

If you click to view the article in its original form, you will see that in that era of medicine, journal articles did not just report averages across the entire cohort, like they do today.

They gave tables that described each patient. Each patient had a row.

Sometimes the articles gave case study narratives to exemplify real patient experiences, in addition to giving tables and graphs.

This change in our reporting methods to numerical tables with averages has hidden from view the individualized nature of thyroid therapy.

For example, the article gave this information in the form of a table:

PATIENT # 1. 47-year-old female.

Fatigue, mental sluggishness, and obesity while on Thyroid.

  • She first tried Thyroid 260 mg (4 grains), for 5 years. Her basal metabolic rate was -5, cholesterol was 165 mg per 100cc, and had no benefit.
  • Then she tried Cytomel, at a dose of 100 mcg/day for 3 months. She had some benefits but also mild side effects.
  • Finally, she tried Trionine at 200 mcg for 1 month. There was no benefit and the side effects were worse.
  • Conclusion: “Cytomel better than Trionine or thyroid.”

PATIENT # 12. 45-year-old male.

Fatigue, dry skin, constipation while on thyroid. Before any therapy, basal metabolic rate was -21 to -17 and cholesterol was high at 220.

  • On thyroid 325mg (5 grains) for 7 years, no benefit.
  • Switched to Trionine 200mcg for 6 months, also no benefit. Then tried Trionine 200mcg & Synthroid 100mcg for 4 months. Experienced benefit!
  • Then moved to Cytomel 100mcg & Synthroid 100mcg for 2 months, no benefit but no side effects either.
  • Conclusion: “Trionine plus Synthroid better than Trionine or thyroid alone or Cytomel plus Synthroid.”

The list goes on. You can see each patient responding differently and many of them experiencing various degrees of side effects of either “thyroxine” or “triiodothyronine / thyroid” medications.

They also tried combinations of desiccated thyroid with T3.

Today’s food for thought

Why are scientists debating whether T3 therapy or combination therapy is “superior” to our current day standard of levothyroxine monotherapy? Why does one have to “win” over another for all patients?

Long ago it was shown that IT DEPENDS on the patient.

Also, in synthetic combination therapy, there is no magic ratio between Synthroid and Cytomel, there is only the ratio that works better or worse for the patient.

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