Thyroid Hormone: T3
Sufficient thyroid hormone is essential to our health and our quality of life. Thyroid hormone has many tissue-specific functions, but
its primary role is to increase the metabolic rate of every cell in the body. It determines the number, size, and activity of the energy-
producing mitochondria that power each cell. Therefore low thyroid levels/effects reduce the function of every tissue and every
organ in our body; including our brain. Because if this, hypothyroidism can produce a wide variety of symptoms including low body
temperature, cold extremities, weight gain, fatigue, need for excessive sleep, muscle aches and stiffness, edema,
dry skin, constipation, scalp and eyebrow hair loss, high blood pressure, depression, and mental slowness. In some
persons, the body reacts to thyroid insufficiency by producing excessive adrenaline, causing a different clinical picture with anxiety,
palpitations, insomnia, and hyperactivity. There are even more symptoms that can be seen in persons due to their unique
constitutions and their bodies' attempts to compensate for the low thyroid levels. Hypothyroidism also has long-term health
consequences. Even mild hypothyroidism increases one's cholesterol levels and one's risk of atherosclerosis and heart attacks.
Hypometabolism promotes weight gain and diabetes. Hypofunction of the immune system can increase susceptibility to infections
and to cancer. Young persons up to age 25 have higher thyroid hormone levels than those over 25, after which there is a steady
decline in our hormone levels, our sensitivity to thyroid hormones, and our own TSH-response to low thyroid levels.
When it comes to diagnosing and treating hypothyroidism, conventional medicine is using the wrong test. Doctors are
taught that all they need to do is look at the TSH (thyroid stimulating hormone) level. They believe that this one blood test tells
them all they need to know about the person's thyroid hormone status--both for diagnosis and for treatment. Dr. Lindner calls this
the "Immaculate TSH Doctrine". This is obviously false; it is contrary to the most basic principles of endocrine feedback control.
The TSH level is not a measure of thyroid hormone levels--only the free T4 and free T3 are. TSH is a measure of how
much the hypothalamic-pituitary system is attempting to stimulate the thyroid gland. A "normal" TSH tells us only that the
person doesn't have failure of the thyroid gland. It does not tell us that they have sufficient levels of thyroid
hormone. A normal TSH does not "rule out" hypothyroidism. Many, and possibly most people with various degrees of
hypothyroidism have normal TSH levels. Their hypothalamic-pituitary system is dysfunctional and not making sufficient TSH to give
them optimal thyroid levels. The hypothalamic-pituitary secretion of TSH is every bit as fallible as the secretion of any other
pituitary hormone or neurotransmitter. Indeed, the hypothalamus is part of the brain and is affected by its connections to all parts
of the brain. It can be dysfunctional due to genetic alterations, neurotransmitter imbalances, toxins, stress, aging, drugs, etc. A
person who has symptoms of hypothyroidism with freeT4 (FT4) and/or free T3 (FT3) levels in the low end of the laboratory
reference ranges and a "normal" TSH has, by definition, central hypothyroidism. In fact, when both T4 and T3 are in the lower third
of their population ranges, the person can be severely hpothyroid, regardless of the TSH level. One woman with FT4 and FT3
levels at the bottom of their ranges, was in a hypothyroid coma. (Mallipedhi 2011) Partial central hypothyroidism is a frequent
cause of depression, obesity, high cholesterol, "chronic fatigue syndrome", and "fibromyalgia". To diagnose hypothyroidism, a
doctor must always look at symptoms first, and the FT4 and FT3 thyroid hormone levels second. The TSH helps only in
assigning the cause of the hypothyroidism. Ultimately, the true test is a trial of thyroid hormone optimization. Improvement with
this trial is the final proof that a person did, in fact, have insufficient thyroid hormone effects.
Even when physicians look at the FT4 and FT3 levels, they fall victim to another errror that Dr. Lindner calls "Reference Range
Endocrinology". (See Why Docs Don't Get It). Reference ranges include almost everyone--95% of some group of persons that
were not screened for symptoms of the hormone tested. With thyroid hormone levels, another problem occurs. Laboratories have
to "validate" the ranges specified by the FT4 and FT3 test kit manufacturers. Rather than go through the time and expense of
testing 200 "apparently healthy" adults, they instead will use the thyroid panels they've run on sick patients with a doctor's order. If
the TSH is "normal", they include the FT4 and FT3 levels in their calculations for their reference range. Therefore the FT4 and
FT3 ranges include patients with partial central hypothyroidism and people being treated with levothyroxine. The Immaculate TSH
doctrine contaminates the reference ranges. Thus the lower end of the FT4 range at most laboratories goes down to 0.8 and
even 0.6ng/dL. On the contrary, in studies of relatively healthy non-patients, without screening for specific symptoms, the 95%
FT4 range is 1.0 to 1.6ng/dL. That means that an adult with a FT4 of 1.0ng/dL is at the 2.5 percentile level; 97.5% of adults have
higher hormone levels! Can that really be considered "sufficient"?.
Unfortunately, there are NO existing studies of the thyroid levels of optimally healthy persons, aged 25 to 30, carefully screened to
make certain that they have no symptoms or signs of hypothyroidism. If such a study were performed, Dr. Lindner predicts that
the 95% statistical range would be 1.3 to 1.6ng/dL. As it is, most labs' reference ranges for FT4 span a factor of 3 from bottom to
top (0.6 to 1.8 ng/dl), and for FT3 a factor of 2. Obviously,a person's health and quality of life will change radically if their thyroid
hormones are lowered or raised by a factor of 2 or 3! The fact that all "normal" values are not ideal is evidenced also in
many studies have shown clear benefits to having FT4 and FT3 levels within the upper third of the reference ranges.
These benefits include lower cholesterol levels, reduced weight, reduced tendency to form blood clots, reduced risk of
atherosclerosis, and alleviation of depression. Thyroid tests must be interpreted in relation to the patient's symptoms. The FT4 and
FT3 tests must be interpreted in relation to each other. A relatively high FT3 may compensate for a relatively low FT4. If the FT4 is
below the middle of the 1 to 1.6ng/dL range, the FT3 should usually be greater than 3.5pg/ml to assure thyroid sufficiency (range 2
to 4.4pg/ml). Thyroid levels, however, cannot be fully interpreted in isolation from a person's cortisol status. When cortisol
levels/effects are low, then thyroid hormone is more active/effective and lower levels are sufficient.
Just as is it completely inappropriate to use a "normal" TSH to exclude hypothyroidism, it is even more inappropriate
to use a "normal" TSH as the goal of thyroid hormone replacement! Obviously, if the TSH production was inadequate to
start with, the TSH will be quickly suppressed with sufficient thyroid replacement. In addition, it is quite clear that even a healthy
TSH-production system is over-suppressed by once-daily oral thyroid supplementation. Our hypothalamic-pituitary-thyroidal
system did not evolve to deal with once-daily oral T4 replacement or to tell doctors what dose to prescribe! Taking all
one's entire day's thyroid hormone by mouth every morning produces an unnatural T4 spike in the blood that over-suppresses the
TSH for 24 hours. Many studies have shown that TSH-normalizing T4 (levothyroxine) treatment leaves many persons with low free
FT3 levels and residual signs and symptoms of thyroid insufficiency (Saravan 2002, Samuels 2007, Baisier 2001). In a landmark
study, four experienced thyroidologists adjusted levothyroxine doses according to clinical criteria only (symptoms and physical
exam). When these patients were tested heir TSH levels ranged from <0.01 (suppressed) to 20mIU/L! Only the FT3 level
correlated well with clinical euthyroidism. (Fraser, 1986). Such a study of clinically-guided treatment has never been repeated. All
research in the thyroid literature is based upon the assumption that a "normal" TSH, with or without treatment, means that the
patient is "euthyroid"--has perfect thyroid sufficiency. All that research is confused and misleading and must be
reinterpreted. Thyroid "specialists" can be conversant with the literature and yet still not know what they are talking
When doctors do prescribe thyroid hormone for an elevated TSH, they prescribe only the prohormone T4 (Synthroid®, Levoxyl®).
T4 must be converted to T3 to become active. They typically will give inactive T4 in low doses that just "normalize" the TSH to any
value within the reference range. The result is nearly universal undertreatment of only one kind of thyroid insufficiency--thyroid
gland failure. The fact that one cannot merely "normalize" the TSH is acknowledged in official guidelines that state that the TSH
must be reduced to the low end if its range, and the statement of a top thyroidologist that the TSH often is suppressed when
people are well-treated and there is no evidence that this is harmful as long as the FT3 is not high. But even this more aggressive
T4 therapy is often not sufficient. There can be poor T4-to-T3 conversion with T4-only therapy. With TSH-normalizing T4 therapy,
FT3 levels can remain relatively low (Escobar-Morreale 1996), and can even be lower than before the T4 therapy was started--
leaving a patient more hypothyroid than before therapy! Yes, small doses of T4 reduce the person's TSH, which reduces both
the thyroid gland's output of T4 and T3, and the body's tendency to convert T4 to T3! The physician, falsely believing he has
restored thyroid sufficiency when he has "normalized the TSH, then ignores the patients' continuing symptoms, or blames their
symptoms on some other cause (e.g. depression, fibromyalgia, etc.). This tragic error is repeated thousands of times daily in clinics
across the world!
The thyroid gland produces both T4 and T3, and T3 is the active hormone, so it makes sense to supply both hormones in
adequate amounts to produce all the benefits of thyroid sufficiency. Armour® thyroid is one of the dessicated porcine thyroid gland
products. It contains both the prohormone, T4 and the active hormone, T3. Fortunately, the pig's thyroid hormones are identical to
ours. Doctor's are taught to disdain dessicated natural thyroid (NDT), yet NDT has a safety and efficacy track record spanning
many decades. It is produced using the latest technologies to assure consistent T3 and T4 content in every tablet--it is held to the
same USP standards as synthetic T4 products. In addition, it provides other hormones and nutrients from the thyroid gland
(calcitonin, T2, iodine, etc.). When we decide to take over the function of the thyroid gland by supplying thyroid hormone orally, it
makes sense to replace everything that our thyroid glands make. It is true that NDT is much higher in T3 than is our normal
thyroidal production. However this is beneficial for oral thyroid therapy as the TSH is low or suppressed on such therapy, and
TSH is necessary for normal T4-to-T3 conversion throughout the body. When we lower the TSH, we must provide more T3.
Finally, there is a great deal of fear among physicians about optimizing hormone levels, especially thyroid levels.
Doctors think that if they give any additional thyroid hormone to a person that lowers the TSH below the reference range, they are
producing hyperthyroidism and will cause bone loss, cardiac abnormalities, and muscle loss. And they believe this no matter what
the FT4 and FT3 levels are! This is, again, the Immaculate TSH Doctrine. As mentioned above, hypothyroidism is most
frequently central, the patient has symptoms and FT4/FT3 levels low in the ranges, and the TSH is inappropriately "normal". Giving
such a person any thyroid replacement will suppress the TSH below the ref. range. Also it appears that even a healthy
hypothalamic-pituitary system over-reacts to once-daily oral thyroid doses, with an excessive reduction in TSH production. TSH
production, after all, evolved to keep the thyroid gland functioning, not to help doctors find the right oral thyroid dose. A low TSH is
not in itself a problem. Consider that low LH production is the cause of low testosterone in most men, and that any testosterone
therapy suppresses that LH level. LH and FSH are suppressed in women taking birth control pills. The TSH level tells us nothing
about the physiology of a person on thyroid replacement therapy. Dr. Lindner has found that, in tests done about 24 to 28
hrs after their last daily dose, most people on adequate NDT therapy have a suppressed TSH. They usually have FT4 levels that
are 1 to 1.3ng/dL, and free T3 levels that are mid-range or high-in-range. The higher FT3 levels on average compensate for the
lower FT4 levels on NDT. These patients have no symptoms or signs of hyperthyroidism--if such occur the dose is reduced. With
levothyroxine therapy alone, the FT4 frequently needs to be above the range, even just to normalize the TSH in primary
hypothyroidism. Dr. Lindner is frequently consulted by patients on T4 therapy are symptomatic. They often have FT4 levels low in
the range and low FT3 levels. A doctor has to learn new skills in order to adjust thyroid doses according to symptoms and the free
hormone levels. Even the free serum FT3 and FT4 levels, with or without treatment, do not tell the whole story. Human physiology
is much more complicated than that. There are many mechanisms by which relative resistance to thyroid hormones can occur.
Some persons may require doses of NDT, or of T3 alone that produce levels well above the reference ranges. In the best
tradition of clinical medicine, a physician should prescribe thyroid hormones as needed to eliminate the symptoms
and signs of hypothyroidism without producing any symptoms or signs of thyroid hormone excess.
TSH-suppression is a frequent result of adequate thyroid optimization and does not equal hyperthyroidism. Thyroid
dosing must be adjusted by symptoms and signs first, and by free hormone levels second. Contrary to old doctor's tales, thyroid
hormone is not a drug that makes anyone feel better. People feel better on thyroid supplementation only if they needed more
hormone. People do not feel well on excessive doses of thyroid hormone--they have palpitations, irritability, sweating,
insomnia, and shaky hands. Typically, on optimal therapy, the TSH is suppressed while the FT4 or FT3 are still within the
population ranges. In order for a doctor to produce hyperthyroidism and its attendant problems, he/she would have to prescribe
grossly excessive doses of thyroid hormone, where the FT4 and FT3 were both high-normal or high. In endogenous
hyperthyroidism, such as occurs in Grave’s disease, the FT4 and FT3 levels are frequently 2 or more times greater than the upper
limit of the reference ranges! Only levels like this can produce muscle wasting. (Riis 2005) Thyroid hormone replacement does
not cause bone loss as is commonly believed; it simply increases all metabolic activities in the body. If a person is already in a
bone-losing state, such as a postmenopausal woman who is not on proper bioidentical hormone replacement therapy, then she will
lose bone faster with better thyroid levels. Excess thyroid hormone can cause heart problems like a rapid heart rate, thickened
heart wall, and poor diastolic relaxation. Again, such persons are usually uncomfortable, their pulse is high, and simply lowering the
dose fixes the problem. Unfortunately cardiac issues can occur even without excessive dosing in susceptible persons. For instance,
atrial fibrillation (a rapid, irregular heartbeat) occurs in 20% of people naturally at some time in their lifetime, and it is more likely
to occur with higher thyroid hormone levels within the ranges as opposed to lower. Risk factors for AF include obesity, sleep
apnea, alcohol, and smoking. Fortunately atrial fibrillation is reversible and its recurrence can be avoided by the use of medication
and/or with lower thyroid doses. Dr. Lindner believes, and most suffering patients would most likely agree, that the chance of
triggering atrial fibrillation in susceptible persons is not a sufficient reason to withhold thyroid hormone optimization from everyone
who needs it.
Reference Range Endocrinology and the Immaculate TSH Doctrine are causing tremendous damage to patients and to
the reputation of the medical profession. Millions of people are suffering needlessly. Undiagnosed and undertreated patients
are organizing and educating themselves through websites like Stop the Thyroid Madness and many other websites and online
groups. One day, this delusional TSH-based thyroidology will be abandoned and physicians will go back to diagnosing and
treating thyroid insufficiency by clinical criteria--according to the patient's signs and symptoms first, and the FT4 and FT3
levels second. In all cases, doctors will seek to identify and treat hormone and vitanutrient deficiencies first, and will use drugs to
suppress symptoms only as a last resort .
To see the evidence from scientific studies for yourself, read through Dr. Lindner's thyroid hormone abstracts.
Draft of academic paper on the inappropriateness of relying on the TSH test to diagnose and treat hypothyroidism.
Response to 2012 AACE/ATA Guidelines on the diagnosis and treatment of hypothyroidism
You can find the 2012 AACE/ATA guidelines here.
For Health and Quality of Life