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The T4 vs. T4/T3 Thyroid Treatment Controversy Continues

Interestingly, some research published during the summer of 2011, and the recently published summary for patients published by the American Thyroid Association (ATA), point up the confusion — and some would say, deliberate obfuscation — of the issue that is still going on in the endocrinology world.

The study was titled: “Levothyroxine Monotherapy Cannot Guarantee Euthyroidism in All Athyreotic Patients.”In plain English — levothyroxine-only treatment (i.e., Synthroid, Unithroid, Levoxyl, Eltroxin, Tirosint, etc.) cannot guarantee normal range thyroid lab results in patients who do not have a thyroid.

Sounds interesting, right?

And what did the researchers find?

Well, simply put, they found that the Free T4 levels were much higher — and Free T3 levels much lower — in the patients treated with levothyroxine, as compared to a control group of people with thyroids who were not on thyroid medication.

The wide range of Free T3/Free T4 ratios showed that individuals have a wide variety in their ability to produce T3, and the fact that TSH levels remained in the so-called normal range, the researches said that this demonstrated “an abnormal feedback mechanism in levothyroxine-treated patients.”

And, more than 20% of the patients, despite having TSH levels in the normal range, did not have Free T3 or Free T4 values in the reference range. The researchers concluded that “A more physiological treatment than levothyroxine monotherapy may be required in some hypothyroid patients.” Again, in plain English — some patients may need a medication that includes T3 in addition to T4.

The authors also stated: “These observations do not allow to take for granted the conclusions, drawn from short-term studies, that levothyroxine monotherapy is adequate for all hypothyroid patients, considering that even subtle abnormalities might have important consequences when lasting for many years or decades.”

Sounds interesting, and promising, especially to the millions of thyroid patients who have to struggle to get doctors to test more than just TSH and evaluate the actual circulating thyroid levels, much less get T3 treatment from mainstream physicians.

But here’s the kicker: The American Thyroid Association — which has a pretty tight relationship with the big pharma levothyroxine drug manufacturers — publishes “Clinical Thyroidology for Patients,” where they find selected research studies, and then summarize them for patients.

And how does the ATA take the above study and “explain” it to patients?

First, they change the implications of the original title. Their summary is called Should patients with no functional thyroid gland be treated with both thyroxine (T4) and triiodothyronine (T3)?

They summarize the general research, and along the way, make this interesting statement: “Recent studies have generally found that there is no clinical advantage in adding T3 to the usual T4 replacement regimen.”

It appears that the writers at Clinical Thyroidology for Patients missed the late 2009 study published in the prestigious European Journal of Endocrinologythat found that where TSH levels were kept consistent, the T4/T3 combination therapy that included 20 mcg of T3 daily was superior to levothyroxine-only treatment, when evaluating for a number of quality of life measurements, depression and anxiety scales, and patient preference. In the study, half the patients preferred the T4/T3 combination — 15% preferred levothyroxine-only — AND, quality of life and other factors were improved.

Back to our friends at ATA’s Clinical Thyroidology for Patients, who summarized the research findings in their own words. (And remember, the original study is saying that T4 alone is not able to maintain normal circulating thyroid hormone levels in some patients, and some may need a medication that includes T3 in addition to T4.) So here’s how they summarize the findings:

“A number of studies have demonstrated that T4 alone is sufficient for the majority of hypothyroid patients. The present study identifies a subgroup of hypothyroid patients, namely those whose thyroid was surgically removed who do not have normal FT4 and FT3 levels despite normal TSH levels on T4 alone. What is not shown by this study is whether or not combination therapy (T4 plus T3) is beneficial in these patients.”

So they have taken a study that says levothyroxine (T4) only treatment cannot guarantee normal Free T4 and Free T3 levels in a subset of patients, and turned it around into a vague statement of what is notshown by the study about the benefits of T4 plus T3 combination therapy, and end up with a question: should patients with no functional thyroid gland be treated with both T4 and T3?

The Bottom Line? When research directly shows the benefit of adding T3 to T4 for hypothyroid patients, as it did in the European Journal of Endocrinology, the mainstream thyroid organizations are not going to tell you about it. Or if they mention it, they’ll dismiss even a top medical journal, and say “Oh, it was a bad study.” If they find a study that suggests something they don’t like, they write a summary that changes around what the study actually says.

Is it any surprise then, that, the work of the National Academy of Hypothyroidism is so desperately needed, educating patients and practitioners about the real science behind hypothyroidism.

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4 Comments on "The T4 vs. T4/T3 Thyroid Treatment Controversy Continues"

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Billie Sullivan

I have been on thyroid medication for 40 yrs. I was taking just T4..never feeling right. .then a dr. Added was life changing. My body started flourishing. My hair started to grow and my nails. I no longer had mood swings. My sleep was better. I wish Drs. Would go by how you feel instead of their research. Most likely none of them have ever suffered with thyroid …

George Wideman

My back, knees, hips, shines, thy bones, muscles hurts to a level of 9 plus. My leg and hand bones ache. My heals hurt and are sore. After sitting or lying down I have great trouble getting up and even straightening up. I was diagnosed as hypothyroid and put on levothyraxin of 5 and have been moved up to 7.5. Pain even seems to have worsen. I really need help soon.

George, first off, it will get better. Take it a little at a time. Get some Magnesium and while you look for help start taking that. It suppresses muscle pain. Next, get your free t3 free t4 and TPOab tested. find a functional doctor near you. Go to and also, There are patient lists that have doctors that people have had success with, and put on the lists. While the lists are not perfect, I’m confident that you will have luck finding at least, and that all you need, someone who is t3 minded and will test and… Read more »

so which thyroid medicine has both T3 & T4?
What should be the reading to take both T3 & T4?

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