Because we cannot (at least at present) extract or undo the effects of a lifetime of organochemical or wheat exposure, we do what is second best: Supplement thyroid hormones when necessary. Most people are subjectively happier—better mood, increased energy, improved tolerance to cold, better bowel function, thicker hair, more successful weight loss—when both T3 and T4 are included either as combination tablets, such as Armour thyroid or NatureThroid, or as two separate tablets of liothyronine (T3) and levothyroxine (T4). Incredibly, the majority of endocrinologists and primary care physicians neglect the T3 thyroid hormone, choosing to only prescribe levothyroxine (Synthroid), even if depression, weight gain, water retention, intolerance to cold, and other phenomena of hypothyroidism persist. It therefore means that it is often necessary to seek out a healthcare practitioner (e.g., a functional medicine practitioner) to obtain full correction of thyroid status that includes T3 assessment and treatment. For many people with thyroid dysfunction, this aspect of thyroid health is crucial and can be sufficient to make or break overall health.

Getting thyroid status “just right” is important. Some simple rule-of-thumb measures that suggest that thyroid status is just right include:

TSH of approximately 1.0 mIU/L (or less than 1.5 mIU/L)
Both free T3 and free T4 in the upper half of the “reference range” (which differs from lab to lab)
Feeling good: i.e., good energy, good mood, freedom from excessive and inappropriate coldness
Oral temperature of 97.3° F immediately upon awakening (lower temperatures suggest hypothyroidism)

Correction of hypothyroidism is also accompanied by many positive side-benefits: people feel more energetic; they are happier; weight loss is accelerated; LDL cholesterol, triglycerides, and Lp(a) values are reduced; and more people enjoy better control over coronary disease risk. The first step in achieving correction of thyroid function is to ensure adequate iodine intake. This is especially important for people who avoid use of iodized salt, exercise or work in hot environments, in people with the low free T4/high TSH pattern, and people with any degree of thyroid enlargement.

The conventional approach to thyroid management, as practiced by most primary care physicians and endocrinologists, is not ideal for health. Given experiences like the HUNT Study, we aim to keep TSH 1.5 mIU/L or less, along with free T3 and free T4 levels in the upper half of the reference range; this has maximized lipid and lipoprotein benefits, generally maximizes a sense of well-being, and has proven practical and effective.

It is also sometimes necessary to look beyond thyroid testing measures to gauge the adequacy of thyroid function. TSH serves as an unreliable index of thyroid function in some people and can be falsely low or “normal” even when hypothyroidism is truly present. Recent data appear to support this argument, with one recent study, for instance, showing that, as we age, the increase in TSH with low thyroid function is 75% less compared to younger people, making TSH an increasingly unreliable index of thyroid function as we age. Attention to symptoms is therefore essential for detecting persons suffering from hypothyroidism underestimated by standard laboratory testing.

Synthetic T4 (e.g., Synthroid®) is not sufficient to resolve symptoms of hypothyroidism in a substantial proportion of persons with hypothyroidism, since not everyone converts T4 to active T3 with equal efficiency. Indeed, low-T3 has been documented to be a predictor of death in patients with congestive heart failure. T3 supplementation has positive effects on psychological symptoms of hypothyroidism with several studies showing that well-being, mood, and cognitive functions are improved; weight loss may also be greater with added T3. T3 supplementation tailored to symptom relief can also address the issue of reverse T3 by providing an external source of effective T3.

Claims that synthetic T4 drugs are superior to natural thyroid drugs in consistency, potency, and stability are false, largely driven by drug industry marketing efforts. The hormones found in porcine (pig) thyroid are chemically identical to that found in humans. Worries over consumption of the animal proteins in desiccated pig thyroid are also unfounded, as they are regularly consumed whenever eating ham, pork chops, or bacon. While this may pose a problem on religious grounds for some people, it offers no impediments on medical grounds. Claims of impurity are also misrepresentation propagated by pharmaceutical marketing. In fact, both Synthroid (synthetic T4) and Armour Thyroid (porcine thyroid) have both had similar struggles with potency and stability in past. Unfortunately, many doctors and patients have only heard about problems with Armour Thyroid. The Department of Health and Human Services has twice issued cease and desist orders to the manufacturer of Synthroid for misleading advertising. Prior to the development of synthetic T4 in the 1950’s, natural thyroid hormone products were the only treatment for hypothyroidism since their introduction in the late 1800’s. In that time, they have developed an extensive track record for safety and efficacy, and products such as Armour Thyroid are now produced under the same USP standards as synthetic T4.

Home Do-it-yourself-at-home thyroid test: Basal body temperature The regulation of body temperature - thermoregulation - is a reflection of the body’s capacity to adapt to the external environment and maintain body temperature within a narrow range. Deviations from the narrow range of body temperature suggest disruption of internal control. If it weren’t for our ability to regulate body temperature, we’d have to lie in the sun like snakes and crocodiles to control body temperature. Should thermoregulation go haywire due to external influences that overwhelm it, trouble results. Anyone who has experienced a fever of 104º F or hypothermia from cold exposure knows that just a few degrees in either direction is distinctly unpleasant, even life-threatening.

What is normal body temperature? Recent analyses, as well as a comprehensive review of temperature data from studies from 1935 to the present, suggest that normal oral temperature ranges from 96.3º F/35.7º C to 99.9º/37.7º C. This differs from the 98.6º F/37.0º C often quoted as normal, a relic of 19th century observations on human temperatures. Body temperature also undergoes a predictable circadian rhythm, with highest temperature of the daily 24-hour cycle at around 8 pm, lowest at around 4 am. It is the temperature low that is most reflective of thyroid status. There is no question that the thyroid gland and thyroid hormones, T3 and T4, play a crucial role in temperature regulation. A principal sign of advanced hypothyroidism (high TSH, low thyroid hormone levels) is low body temperature, while hyperthyroidism (low TSH, high thyroid hormone levels) is associated with increased body temperatures. When can low temperature be attributed to hypothyroidism and not other causes? There are frustratingly few data that explore this relationship. While there is no dispute that low temperatures can accompany hypothyroidism, it is not clear how reliable an indicator it is, since the relationship has not been studied in a formal manner. In anecdotal experience in many clinical practices, however, low body temperature is commonly used to identify hypothyroidism.

We have used first-upon-arising oral temperatures in the Cureality program and they can indeed be useful. At a practical level, any first a.m. temperature (immediately upon arising) consistently less than 97.3º F or 36.0º C is suggestive of hypothyroidism; the lower the temperature, the more likely it represents hypothyroidism. A temperature of 94.7° F, for instance, is more strongly suggestive of hypothyroidism than a temperature of 97.1° F. Followers of the experience of Dr. Broda Barnes adhere to his original belief that axillary (armpit) temperatures are the preferred method to assess body temperature. However, of the various ways to measure body temperature, axillary is the least reliable and the one most prone to inaccuracy. More so than other methods, axillary temperatures are subject to external ambient temperature, amount of clothing worn, sweating, whether right or left arm is used (since there is variation of up to 2.0° F degrees from right to left), the amount of cutaneous (skin) dilation or constriction of blood vessels. Axillary temperatures track internal (rectal) temperature poorly, with wide variation in the day-to-day and minute-to-minute fluctuations of temperature, and especially marked divergence from rectal temperature in morning (temperature nadir) and evening (temperature peak) hours, with as much as 1.8-2.7º F/1.0-1.5º C variation within several minutes.

Axillary temperatures are therefore too variable and unreliable for use in assessing thyroid status and should not be used. Despite its uncertainties, temperature is still a useful tool to identify hypothyroidism, particularly when laboratory values like TSH, free T3, and free T4 are borderline or equivocal, or when symptoms are unusual or atypical. Low temperature may suggest low thyroid status even when all other measures, including TSH, are normal, but this is on more shaky ground scientifically. Temperature can also be useful to follow trends over time to gauge the adequacy of thyroid replacement.