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Thyroid Hormones

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Maybe you’ve heard of the “butterfly effect:” the theory that even tiny changes can have big consequences, such as the distant flapping of a butterfly’s wings later causing a hurricane. That idea also applies to the thyroid, a gland in the neck that happens to be butterfly shaped. It’s small, but its role in the body is huge.

Thyroid hormone (thyroxine) controls how quickly each of our cells uses energy and is vital to cell health. It also regulates all of our metabolic systems: those controlling body fat, bone composition and energy. From the very beginning, it’s involved in our neuronal development, which means that it infuences our nervous system, cognition and thinking.

In young people, it influences growth. A poorly functioning thyroid gland can even stunt a child’s intellectual development. When the thyroid is even a little bit out of a whack, the effects can be dramatic—it can cause a hurricane. An off-kilter thyroid isn’t always easy to identify, however. That’s because the thyroid has an impact on so many of the body’s systems that the symptoms can be wide-ranging.

There are two types of thyroid imbalances. A person who’s producing too much thyroid hormone is said to have hyperthyroidism. While this condition is very serious, it’s comparatively rare— only about one to two percent of the population has it. We’ll discuss hyperthyroidism in more detail subsequently.

We’re focusing first on underactive thyroid, or hypothyroidism, which is far more common, affecting at least 4 to 5 percent of people, or possibly more—maybe even as much as 8 to 10 percent of us. That may be why thyroid hormone, levothyroxine, has been one of the most commonly prescribed drugs in the country for years.

Underactive Thyroid

” There is no correlation between [the degree of] deficit a person has and her symptoms.

Ridha Arem, MD

Dr. Arem has seen lots of people whose blood tests indicate severe hypothyroidism “walking around basically without any symptoms,” whereas “other people who have a minute deficit may have a lot of symptoms.”

Symptoms of Low Thyroid

  • Apathy
  • Depression
  • Tiredness
  • Weakness
  • Fatigue
  • Mental fogginess and decreased concentration
  • Clumsiness
  • Dry skin
  • Brittle fingernails
  • Hair loss
  • Puffy eyes
  • Hoarse voice
  • Constipation
  • Sensitivity to cold
  • Decreased sweating
  • Swollen hands or legs
  • Carpal tunnel syndrome
  • Elevated cholesterol
  • Shortness of breath during exertion
  • Slow pulse
  • Anemia
  • Heavy menstruation
  • Infertility

Some of the most common symptoms of hypothyroidism include tiredness or lethargy, depression, diffculty focusing, constipation and sensitivity to cold. Sometimes a person’s core body temperature will actually drop. That explains why a person who suspects an underactive thyroid is sometimes advised to take her temperature before rising in the morning.

Weight Problems

Another frequent complaint is weight gain, especially from fluid retention. Many people have trouble losing weight, even if they cut calories and exercise. Adding to the frustration, people with hypothyroidism may feel too tired to exercise, and an underactive thyroid can reduce muscle strength and cause shortness of breath during exertion.

All of that can make keeping the pounds off challenging. (Weight gain may not be as pronounced a symptom as people often think, though. Generally, it’s not more than five or ten pounds. Once thyroid hormones have been regulated, a person’s exercise efforts and attention to diet should fnally pay off.)

Hair and Nails

A number of people also suffer from brittle nails, dry skin and coarse hair. It’s common for hypothyroidism to cause people’s hair to fall out more than usual as well; if you’re missing hair from the outer edges of your eyebrows, that’s a pretty good indication that your thyroid isn’t working well. People may also lose hair from their legs, underarms, and pubic area. (Once the thyroid is balanced properly, your hair should grow back.)

Other Symptoms

If your doctor suspects an underactive thyroid, she’ll likely check for a slow Achilles reflex, puffiness around the eyes, and swollen fingers. She’ll probably also feel your neck to find out if your thyroid gland is enlarged. (A swollen thyroid gland is called a goiter.) She’ll likely ask female patients about their periods; heavy bleeding is another possible sign of hypothyroidism, and women with inadequate thyroid may have trouble getting pregnant.

Even if you’re experiencing several of these symptoms, your doctor can only confirm your diagnosis with a blood test. Diagnosing hypothyroidism has become somewhat controversial. Doctors disagree on what qualifes as a “normal” range of thyroid hormone, on which tests are needed to verify a diagnosis, and even on the best treatment.

In general, though, the treatment is straightforward: daily supplementation with thyroid medication. Most often, doctors prescribe the synthetic hormone levothyroxine. It is available under brand names Synthroid, Levoxyl or Levothroid. However, some doctors may prescribe natural thyroid hormone instead. (That’s something we’ll also address in more detail below.)

Prevalence and Causes of Hypothyroidism


Dr. Ridha Arem believes that a person’s antioxidant intake can affect her thyroid health, too, and that if she’s deficient in certain micronutrients or minerals, for instance selenium, that deficit may negatively influence her thyroid. He also recommends that people take calcium (1,000 mg) and magnesium citrate (200 to 400 mg) several hours apart from thyroid hormone (Arem, The Thyroid Solution Diet, pp. 189-191).

Iodine is an integral component of thyroid hormones. In fact, they are named T3 and T4 to indicate how many atoms of iodine the molecule contains. T3, or triiodothyronine has three iodine atoms, while levothyroxine, T4, has four. You may ask if you need iodine supplements to support the thyroid. In the US, common table salt is iodized to prevent goiter. Generally, people don’t need iodine supplements, but one group of individuals might. German researchers have found that approximately one-third of the vegans in one study were deficient in iodine (Weiker et al, “Vitamin and mineral status in a vegan diet,” Deutsches Arzteblatt, Aug. 31, 2020). Presumably, this is because they are not getting iodine from dairy products, eggs, fish or seafood. In the US, young women under 40 are also at risk for insufficient iodine intake. Dr. Tieraona Low Dog explains this in detail in her excellent book, Fortify Your Life: Your Guide to Vitamins, Minerals, and More (National Geographic, 2016).

Some people promote the use of kelp or other seaweed products as sources of iodine to bolster thyroid function. While seaweed can provide iodine in the diet where it is a traditional part of the eating pattern, taking supplements made of seaweed can backfire, especially if the thyroid gland is already out of balance. Excess iodine can exacerbate thyroid dysfunction (Leung AM & Braverman LE, “Iodine-induced thyroid dysfunction.” Current Opinion in Endocrinology, Diabetes, and Obesity, Oct. 2012; also, Farebrother J et al, “Excess iodine intake: sources, assessment, and effects on thyroid function,” Annals of the New York Academy of Sciences, June 2019).

There are also botanical products that may mimic thyroid hormone in the body. They include:

  • Asian ginseng
  • Bladderwrack
  • Capsaicin
  • Echinacea
  • Forskolin

Sadly, there is no evidence that such supplements are helpful, and they can sometimes cause problems, especially for individuals with the autoimmune condition Hashimoto’s thyroiditis (ATA/AACE Guidelines, 2012).

Every year, approximately 100 million prescriptions are dispensed for supplementary thyroid hormone medications such as Levothroid, Levoxyl, levothyroxine, Synthroid, Tirosint, and Armour Thyroid. That makes hypothyroidism one of the most commonly treated conditions in the United States. For years, Synthroid has been among the most prescribed brand-name medications.

This hasn’t always been the case. Several of the experts we’ve interviewed for The People’s Pharmacy radio program have offered compelling theories for why this disorder may be more common now than it was in decades past.

Better Tests

For one thing, doctors have become much more knowledgeable about testing. Dr. Deepa Kirk, assistant professor in the Department of Medicine in the division of Endocrinology and Metabolism at the University of North Carolina at Chapel Hill, has noted that a person used to need to have fairly dramatic, advanced symptoms before a doctor would test him for hypothyroidism. Now, thyroid hormone levels are one of the things that many doctors routinely check, especially if a person has symptoms or a family history. A lot of patients have become savvier, too, so they’re more likely to go to the doctor if they don’t feel right. Part of the reason that more people are being diagnosed with hypothyroidism, in other words, is that more people are being tested for it.

Environmental Factors

There may be other reasons that diagnoses are on the rise. Dr. Ridha Arem, Director of the Texas Thyroid Institute in Houston, Clinical Professor of Medicine at Baylor College of Medicine, and author of The Thyroid Solution and The Thyroid Solution Diet, has pointed to “the incidence of autoimmune thyroid disorders—the immune attacks on the thyroid that cause thyroid imbalance” and believes that “there has probably been an increase in these incidences related to the environment, primarily.”

By environment, he means both things like stress—“there’s a signifcant link between stress, the immune system, and the thyroid,” he says—and chemicals: pesticides, herbicides, and other things that affect the thyroid hormone receptor, thyroid hormone effciency and the health of the thyroid gland.

Dr. Kirk agrees. While she acknowledges that the data linking thyroid disease and environmental causes “are not entirely clear,” she told us that an estimated “70 percent of thyroid dysfunction is due to autoimmune causes,” while “the other 30 percent is probably explained by environment.”

Dr. Kent Holtorf has a similar point of view. He’s a family practice physician, Founder and Director of the Holtorf Medical Group, and creator of the National Academy of Hypothyroidism. He notes that bisphenol A (BPA), found in many plastics, “will actually block thyroid receptors,” and that pesticides, plastics, and pollutants have a similar effect. Research in China shows a link between exposure to PBDE compounds from e-waste recycling and thyroid hormone disruption (Xu X, Liu J, Zeng X et al, “Elevated serum polybrominated diphenyl ethers and alteration of thyroid hormones in children from Guiyu, China.” PLoS One 2014 Nov 21;9(11):e113699. doi: 10.1371/journal.pone.0113699)

Genetic Factors

Genetics can also play a role in whether or not a person will suffer from a thyroid condition. If your parents or grandparents had thyroid imbalances, you’re more likely to develop them. A susceptibility to autoimmune problems may be inherited, so even a family history of other autoimmune diseases such as diabetes or lupus could increase a person’s risk. Sex hormones are also relevant, which is why hypothyroidism primarily affects women. “In general, ten women to one man are affected by thyroid autoimmunity,” according to Dr. Arem. Women also have fewer thyroid receptors than men, so they’re more sensitive to fluctuations of thyroid hormone.

Some medications can affect thyroid tests, and in some cases, thyroid hormone levels. For a list, keep reading.

What Is Normal?

What Is Normal TSH?

Many doctors disagree about what constitutes a “normal” amount of thyroid hormone in the body, and the TSH test has become especially controversial. Some doctors think that a TSH number of 5 is normal and don’t want to treat patients unless TSH is close to 10. Recent studies suggest that the upper limit of normal may be closer to 3, or even 2.5. The arguments may sound arcane until a patient finds himself without a definite diagnosis–and sometimes without a treatment plan.

T3 and T4

The thyroid gland normally puts out both T3 and T4 (also known as triiodothyroxine and levothyroxine, respectively). Interestingly, even in healthy people, the thyroid produces only a small amount of the T3 that the body actually needs–about 20 percent, according to Dr. Arem. It converts the other 80 percent from T4. As a result, there’s always far more T4 circulating in a person’s system than T3 , but T3 is more metabolically active. It also lasts for a shorter time.

Unlike the IRMA, which measures what the pituitary gland in the brain is doing, tests that look at T3 and T4 levels reveal how much thyroid hormone is really circulating in a person’s system. It stands to reason that if a person seems to be suffering symptoms of an imbalanced thyroid, a doctor who specializes in thyroid dysfunction will often also measure what’s happening with T3 and T4.

As we mentioned earlier, thyroid disorders can only be confirmed with blood tests, primarily TSH. But what counts as low? And, far more controversial, what’s considered high? As recently as a decade or so ago, Dr. Kirk explained, “TSH could be as high as five or six or seven, and we would say you are normal. These days, if it’s three or four, we’d say you have early thyroid disease.” In its review of research, the American Association of Clinical Endocrinologists found the upper level of TSH in healthy people ranged from 2.5 to 4.5 (ATA/AACE Guidelines, 2012).

What about the opposite problem? Sometimes the test says that TSH is “normal,” but the individual nonetheless has a laundry list of symptoms that suggest something’s off. Occasionally, as Dr. Kirk explained: “There is a very small subset of people who have a totally different thyroid disease, where the thyroid gland is fine but the signals from the brain are not reaching the thyroid.”

In fact, some experts believe that for a very large number of people, not a small subset, the TSH is not accurate enough by itself. Dr. Holtorf, for instance, believes that TSH testing “misses up to 80 percent of people with low thyroid.” Factors like “stress, weight gain, dieting, chronic illness, and inflammation will all suppress the thyroid levels inside the cells, [yet] the [TSH] test will be normal.”

Likewise, author and patient-health advocate Mary Shomon believes that TSH often won’t show that a person’s suffering from autoimmunity, “the primary cause of an underactive thyroid in the U.S.”

What should you do if there’s a discrepancy between how you feel and what your IRMA test for TSH indicates? We recommend that you see a doctor who will order more tests, not just of TSH, but also of what Dr. Kirk calls “the actual thyroid hormone levels,” which are called T3 and T4.

Beyond TSH: Other Thyroid Hormone Tests

Normal Values of Thyroid Tests

Total T44.5-12.5
Serum T375-180
TBG capacity15-25 mcg T4/dl
Free T40.7-1.9
Free T380-180
TPOAbvaries by lab
T3 Resin Uptake25-35%

Doctors rely most on a test called an immunoradiometric assay (IRMA), which measures how much thyroid-stimulating hormone (TSH) is circulating in the body. (TSH may also be called thyrotropin.) The IRMA is a bit counter-intuitive: when TSH levels are high, that actually means that thyroid levels are too low; when the TSH number is low, it means the thyroid hormone level is too high. If the thyroid gland isn’t making enough hormone, the brain churns out more TSH to try to get the gland to ramp up production. If there’s too much thyroid in the blood, the brain will dial back the TSH. , In some circumstances, it can drop to near zero.

Generally, thyroid specialists will look at a patient’s total serum T4 and serum T3, as well as her free T3 and T4. (Thyroid hormone mostly moves through the body by binding to proteins, like thyroxine-binding globulin, or TBG. But only the unbound, or “free,” hormone is active metabolically. To get a full picture of what’s happening with the thyroid, doctors look at the levels of all of these different forms of the hormone.)

Because T3 and T4 measure how much thyroid is actually in a person’s body, the numbers will be low in someone with hypothyroidism. That’s in contrast to TSH, which will be high. (Of course for hyperthyroidism, the opposite will be true.)

Doctors may also check for thyroid peroxidase antibodies (abbreviated as TPO), which indicate autoimmunity. Health advocate Mary Shomon believes that a panel of four tests—those that measure TSH, free T3, free T4, and TPO—should be enough to point out an underlying thyroid condition and to help a patient and her doctor begin to formulate a plan.

Less commonly, some thyroid specialists—often those with what’s sometimes termed “an alternative approach”—may also look at reverse T3, which is thyroid hormone that your body is making but, for some reason, not using. In other words, it’s not being converted effciently. Dr. Holtorf, for example, considers an analysis of the reverse T3 : free T3 ratio as “probably the best laboratory test to determine the thyroid activity in the tissue.”

Additionally, some doctors, like Dr. Holtorf, may order a test to look at sex-hormone-binding globulin. (It increases in response to either estrogen or thyroid. If estrogen is fine, then a thyroid imbalance may be suspected.) Dr. Holtorf also checks what’s called the “relaxation phase” of a muscle reflex, and he does basal metabolic testing as well.

Not all specialists will order all of these tests to check thyroid function. They may not all be required. The important take-away message is this: if your doctor tells you that your TSH is in the usual range and your thyroid levels are therefore “normal” but you nonetheless feel unwell and are suffering symptoms of an under- or overactive thyroid, it may be necessary to get more comprehensive testing, perhaps under the supervision of a different doctor. Your doctor should be willing to share your test results with you and to explain what they mean.

In the Gray Zone

Other Drugs

Before undergoing any thyroid testing, you should tell your doctor about every medication that you are taking. There are many drugs for unrelated conditions that can affect thyroid hormones and influence the accuracy of tests, especially a test called the RIA, which measures serum total T4. There is a partial list below.

Many doctors disagree about what constitutes a “normal” amount of thyroid hormone in the body, and the TSH test has become especially controversial. Some doctors think that a TSH number of 5 is normal. Others think that this is much too high, and believe that 3, or even 2.5, is at the upper limit of normal. The difference between 3 and 5 may sound insignifcant, but millions of people fall within the gray zone, and some of them feel pretty awful.

Some doctors will medicate gray-zone patients with a low dose of thyroid hormone, but many prefer not to. As Dr. Kirk has said, “I always caution [these] patients not to expect great things, because even if they do have thyroid dysfunction, it’s mild, and typically, I don’t see a lot of great reversal of [their] symptoms.” She has also pointed out the hazards of over-treating patients, which can be a particular risk with patients so close to the normal range: “if that TSH number all of a sudden falls to zero, again, you end up with a whole lot of other problems,” she cautioned. (The other problems are mostly hyperthyroid symptoms.) Moreover, once a person is on thyroid supplementation, she’s generally on it for life, so starting on medication shouldn’t be undertaken lightly.

On the other end of the spectrum, there are some patients whose blood tests show that they have a thyroid imbalance, but it’s subclinical—that is, the person isn’t experiencing any symptoms. Some of them may not understand the point of starting on medications in this case. But many doctors recommend treatment, as they believe it will protect the cells and bodily systems that the thyroid regulates.

Medications That May Affect Thyroid Tests*

*This list is incomplete; new drugs are released onto the market too frequently for it to be entirely comprehensive. There are also a number of drugs and supplements that can interact negatively with thyroid medications. That is covered in the section on Drugs & Supplements That Interact with Thyroid Medication.

amiodarone (Cordarone)Total T4, serum T3, reverse T3, TSHRaises T4, lowers T3, and increases rT3 and TSH. Abnormal tests may persist weeks or months after drug is discontinued. Drug may trigger thyroid function problems in some patients.
anabolic steroids (testosterone, etc.)Total T4, serum T3, TSHLowers test values; levothyroxine dose may need reduction
aspirin (high dose)Total T4Lowers reading without affecting thyroid function
carbamazepine (Tegretol)Total T4, T3 resin uptake, othersLowers test values. In combination with other anticonvulsants, may affect thyroid function
corticosteroidsTotal T4, serum T3, TSHLowers test values
estrogen (Estrace, Estraderm, Premarin, etc.)Total T4Raises reading without necessarily affecting thyroid function
haloperidolTSHTSH value may be high.
heparinTSHTSH value may be low.
iodine-containing contrast mediaAllThyroid function tests may be altered up to a few years after the x-ray or myelogram.
lithiumAllReadings may be altered indicating reduced thyroid function. In some cases, thyroid function is suppressed.
metoclopramide (Reglan)TSHTSH tends to be higher
oral contraceptives (Demulen 1/50, Norlestrin, Ovral, etc.)Total T4Raises reading without necessarily affecting thyroid function
Parkinson’s disease drugs (Parlodel, Sinemet, Symmetrel)TSHTest value lowered
phenytoin (high dose)Total T4Lowers reading without affecting thyroid function
perphenazine, longterm (Trilafon)Total T4Raises reading without affecting thyroid function
propranolol (doses > 160 mg/day)T3, serum T4Serum T3 decreases; serum T4 may increase without change in thyroid function.
salsalate (Disalcid)Total T4, serum T3Test readings are signifcantly lower; thyroid function is not altered.
tamoxifen (Nolvadex)Total T4Raises reading without affecting thyroid function

Treating Underactive Thyroid

Generic Levothyroxine

“I had been taking Synthroid for about 15 years when I changed insurance and started getting prescriptions from a mail order pharmacy. They substituted a generic, and very soon I started gaining weight. I’ve never had a problem with weight before. I couldn’t get enough sleep, and my hair and nails became brittle. I went to my MD who checked my thyroid levels and said they were OK.

“I went online to search for thyroid problems and found lots of reports of the same problem with the generic. I asked my doctor for a prescription for the Synthroid brand and my symptoms disappeared within days! Insurance won’t pay for the brand, so I have to pay for it myself. It is quite expensive, almost a dollar a pill.”

We suggest:

Stick with the same maker, whether you take brand or generic levothyroxine.

Most experts agree that whether you take thyroid supplements in the morning or evening, consistency is key. That’s the best way to regulate the dose.

Hypothyroidism is treated with thyroid hormone supplements, either natural or synthetic. The primary ingredient of natural medications is the dried, powdered thyroid of pigs or cows. It’s been on the market for more than a century and is still available as Armour Thyroid, Nature-Throid, Westhroid, or in generic form as Acella. There are patients who swear by it, but many endocrinologists prefer prescribing synthetic levothyroxine, because they worry that the dosages of natural hormone are harder to control and that potency can change batch to batch.

Synthetic levothyroxine, or T4, is available as Synthroid, Levothroid, Levoxyl, Unithroid, and Tirosint. Each of these comes in a wide range of dosages. (Tirosint, for example, is available in 13, 25, 50, 75, 88, 100, 112, 125, 137, and 150 mcg dosages. It is the only one of the medications listed above that comes in a liquid capsule form; the others come in tablets. That’s relevant because it means that Tirosint can’t be broken down into even smaller dosages, e.g., for children.)

The reason that these medications come in so many dosage sizes is that doctors aim to prescribe the smallest possible amounts that will bring their patients’ TSH numbers into the normal range. Prescribing too much hormone can cause people to suffer the dangerous symptoms of an overactive thyroid (which will be discussed in more detail below). Doctors generally prescribe a small dose to start with and then incrementally increase it.

Even after a person’s dosage has been calibrated, though, it’s not set for life. Thyroid hormone levels can fluctuate due to a number of factors, from age, to pregnancy, perhaps even to the changing of the seasons. A study published in Frontiers in Endocrinology (Feb. 24, 2021) reveals that TSH levels tend to be higher in the winter. That means the thyroid gland may not be working as well during the darker and colder months.

If you start to feel the return of your hypothyroid symptoms, don’t hesitate to get in touch with your doctor. If you feel that your medication isn’t working properly, it might not be, and may need to be increased. Dosages occasionally need to be decreased as well, for example in patients who develop heart conditions.

Levothyroxine is absorbed best when it’s taken on an empty stomach. For years, the conventional wisdom was that it needed to be taken in the morning, at least half an hour to an hour before breakfast. But some studies suggest that taking it before bed (at least four hours after eating) can work just as well and may perhaps be even more effective. (See, for instance, Rajput R, Chatterjee S, Rajput M, “Can Levothyroxine Be Taken as Evening Dose? Comparative Evaluation of Morning versus Evening Dose of Levothyroxine in Treatment of Hypothyroidism.” J Thyroid Res. 2011;2011:505239 and Bolk N, Visser TJ, Nijman J et al. “Effects of evening vs. morning levothyroxine intake: a randomized double-blind crossover trial.” Arch Intern Med. 2010 Dec 13;170(22):1996-2003.)

That’s good news for java lovers, because coffee is one of several things that can prevent proper absorption of thyroid medication. For that reason, people are generally told to wait at least an hour after taking their morning thyroid dose before drinking coffee, and that can be tough. (One beneft of Tirosint is that it seems liquid capsules are absorbed well even if taken with coffee. See, for instance, Vita R, Saraceno G, Trimarchi F, et al, “A novel formulation of L-thyroxine (L-T4) reduces the problem of L-T4 malabsorption by coffee observed with traditional tablet formulations.” Endocrine. 2013 Feb;43(1):154-60.)

Drugs & Supplements That Interact with Thyroid Medication

Factors that May Require a Change in Dose

  • Aging
  • Malabsorption
  • Celiac disease
  • Pregnancy
  • Thyroid surgery
  • Treatment with other drugs or supplements, including:
  • Carafate
  • Cordarone
  • Dilantin
  • Estrogen
  • Gleevec
  • Iron
  • Questran
  • Rifampin
  • Sutent
  • Tegretol
  • Testosterone

There are several other things that, like coffee, should not be taken at the same time as thyroid medication. Among them are iron and calcium supplements, which may reduce absorption of thyroid drugs. (Taking either supplement at least four hours before or after taking a dose of thyroid medication avoids the problem.)

Another supplement that can wreak havoc is biotin. At high doses, this vitamin can interfere with commonly-used blood tests for TSH. The consequence is TSH readings that are artificially low, or possibly even undetectable, leading to a false diagnosis of hyperthyroidism (see De Roeck Y et al, “Misdiagnosis of Graves’ hyperthyroidism due to therapeutic biotin intervention.” Acta Clinica Belgica, Oct. 2018; 73(5):372-376. In addition, Charles S et al, “Erroneous thyroid diagnosis due to over-the-counter biotin.” Nutrition, Jan. 2019; 57: 257-258. Also Bowen R et al, “Best practices in mitigating the risk of biotin interference with laboratory testing.” Clinical Biochemistry, Dec. 2019; 74: 1-11.) Dr. Bowen and colleagues suggest that a person might stop taking biotin several days before blood is drawn for testing. Exactly how many days is difficult to say, because it depends on renal function (biotin is cleared via the urine and renal dysfunction will alter biotin clearance), biotin dose, length of time already on biotin, the person’s metabolism of the biotin and its half life in blood, the analyte being tested and the assay from the manufacturer. Some manufacturers recommend a minimum of two to three days off biotin before testing for thyroid function.

There is a considerable list of prescription and over-the-counter drugs that may interact badly with thyroid pills, possibly causing unwanted side effects. This is true for asthma drugs, certain heart medications, lithium and even antacids.

You should never discontinue any medication without consulting your physician. But you should also be sure to talk to your doctor and pharmacist about all of the medications and supplements that you take in order to avoid a drug interaction. Once a thyroid condition has been diagnosed, medication is generally required for life, so you may need to have this conversation with your doctor several times if other conditions appear and other medications are added to your regimen.

People with a range of gastrointestinal disorders may not absorb levothyroxine tablets well (Castellana M et al, “Prevalence of gastrointestinal disorders having an impact on tablet levothyroxine absorption: should this formulation still be considered as the first-line therapy?” Endocrine, Feb. 2020; 67(2):281-290.). People with celiac disease, lactose malabsorption, H. pylori infection or various autoimmune digestive conditions may need to take thyroid hormones in a form that would be more readily absorbed.

Many health professionals and most patients are unaware of an interaction between acid-suppressing drugs called proton pump inhibitors (PPIs) and levothyroxine. Researchers have found that people who take drugs like esomeprazole (Nexium), omeprazole (Prilosec) or pantoprazole (Prevacid) may result in elevated TSH levels, due to low absorption of the thyroid hormone (Trifiro G et al, “Drug interactions with levothyroxine therapy in patients with hypothyroidism: observational study in general practice.” Clinical Drug Investigation, March 2015; 35(3):187-195.).

Hypothyroidism & Pregnancy

Women with an untreated underactive thyroid may have trouble getting pregnant. Once a woman with hypothyroidism becomes pregnant, the hormonal changes she experiences may also affect her thyroid production, and her dosage may need to be changed accordingly. (Women may need increased doses during pregnancy.)

Pregnancy can make thyroid tests somewhat more difficult to interpret (as can the hormones in birth control pills), so many specialists are likely to take a look not just at a pregnant woman’s TSH (which should be tested every trimester) but also at her free T4.

Getting the thyroid tested during pregnancy is very important: if hypothyroidism is left untreated, there are risks of complications for both mother and child.

Some Drugs that Interact with Thyroid Hormone

You can listen to our interview with Dr. Kirk, Dr. Holtorf and Mary Shomon on CD or mp3. Look for Show 853: Thyroid Controversies

antacidsAluminum- or calcium-containing antacids may interfere with thyroid hormone absorption.
androgens (testosterone, etc.)Androgens increase the effects of thyroxine. Lower dose (25-50%) may be needed.
antidepressants (tricyclics, eg. Elavil)Thyroxine increases tricyclic action; more side effects possible from both drugs.
antidepressants(SSRI, eg. Prozac) Rare reports of thyroid dysfunction
asthma medicine (theophylline)Hypothyroid people metabolize aminophylline and theophylline slowly; upon starting thyroxine, they may need a higher dose of asthma medicine.
bisphosphonates (Actonel, Boniva, Fosamax, Zometa)Interfere with thyroxine absorption
charcoalReduces thyroxine absorption
cholesterol bile acid drugs (Colestid, Questran, Welchol)Interfere with thyroxine absorption
chromium picolinateReduces thyroxine absorption
ciprofoxacinReduces thyroxine absorption
diabetes medicine (metformin)Metformin reduces TSH secretion in hypothyroid people.
epilepsy drugs (carbamazepine, phenytoin, valproate)All except levetiracetam may suppress thyroid gland so that treatment is needed.
heart drugs (amiodarone)May suppress thyroid gland so that treatment is needed
heart drugs (beta blockers)Increase in thyroxine may reduce effectiveness of beta blockers; beta blockers may reduce conversion of T4 to T3
heart drugs (digoxin)Blood levels of digoxin may drop as levels of thyroxine rise.
heartburn drugs (H2 blockers, eg Tagamet)Interfere with thyroxine absorption
heartburn drugs (PPIs, eg. esomeprazole)Interfere with thyroxine absorption
interferon alfa (Intron A)Long-term use may lead to thyroid antibodies and thyroid malfunction.
iron supplementsLike aluminum and calcium, iron reduces thyroxine absorption. It is unclear whether other minerals would have a similar effect.
lithium (Eskalith, Lithane, Lithobid, etc.)Can cause thyroid enlargement (goiter), hypothyroidism or, rarely, hyperthyroidism. (Causes hypothyroidism in roughly 20% of patients within their first two years of use.)
niacin (nicotinic acid)Lowers total T4 and thyroxine-binding globulin (TBG)
orlistat (Alli, Xenical)Reduces thyroxine absorption
raloxifene (Evista)Reduces thyroxine absorption
St. John’s wortIncreases TSH secretion

Balancing T3 & T4


When patients receive the proper dosages of thyroid medications, they shouldn’t experience side effects. However, because even tiny changes in thyroid hormone can have big effects on the body, overmedication needs to be carefully guarded against. Ongoing overmedication can result in very serious medical complications, including damage to the cardiac and nervous systems.

If you start to experience heart palpitations, rapid heartbeat, insomnia, nervousness, high blood pressure, tremor, diarrhea, headache, increased sweating, changes in appetite, weight loss, or decreased menstrual flow, you should see your doctor right away, as these may be symptoms of too much thyroid. Older people are susceptible to the heart rhythm disturbance called atrial fibrillation, while postmenopausal women may develop osteoporosis.

You should also see your doctor if you continue experiencing low-thyroid symptoms.

As we mentioned earlier, some doctors disagree not only on who should be treated for hypothyroidism, but on how they should be treated, i.e., with which medications. One controversial topic is whether or not patients require only T4 supplementation, or if some of them do best with both T3 and T4.

Because the body naturally converts T4 to T3, it’s understandable that many doctors think supplemental T4 (levothyroxine) should be all that’s needed to get both T3 and T4 levels into the normal range, and thus to get TSH down too. For many people, that’s true. But for some, T4 alone doesn’t seem to rid them of their symptoms. Dr. Ridha Arem believes that a number of patients “have consequences with respect to energy level, mood, metabolism, etc. For optimal wellness,” he says, “they need a treatment that combines T4 and T3.”

Dr. Kent Holtorf notes that “if a person’s healthy, not stressed and not depressed [and] doesn’t have any chronic illness, T4 [alone] is probably okay. But the sicker you are, the more likely [it is that] you [will] need T3.” He believes that when this population of sick patients is given T4, their bodies turn it into reverse T3 instead of metabolically active, useful T3, which is why they continue to suffer hypothyroid symptoms. If T4 is converted into reverse T3, he explains, “it goes in that keyhole”—the receptors where active T3 is supposed to go—“and basically doesn’t do anything. It blocks the thyroid from going into that receptor, so [reverse T3] is an anti-thyroid. And the more stressed [a person is], the more inflammation [she has], the more chronic illness [she’s experiencing], the more likely [she is] to make reverse T3.” He concludes that such patients need proportionately more T3.

The idea that T4 and T3 may need to be balanced is beginning to gain some ground as more studies are done that suggest the benefts of this approach for some patients. (See, for instance, Wartofsky L. “Combination of L-T3 and L-T4 therapy for hypothyroidism.” Curr Opin Endocrinal Diabetes Obes. 2013 Oct;20(5):460-6, Biondi B, Wartofsky L, “Combination treatment with T4 and T3: toward personalized replacement therapy in hypothyroidism?” J Clin Endocrinal Metab. 2012 Jul;97(7):2256-71, Wiersinga WM, “Do we need still more trials on T4 and T3 combination therapy in hypothyroidism?” Eur J Endocrinol. 2009 Dec;161(6):955-9, and McDermott MT, “Does combination T4 and T3 therapy make sense?” Endocr Pract. 2012 SepOct;18(5):750-7, McAninch EA & Bianco AC, “The swinging pendulum in treatment for hypothyroidism: From (and toward?) combination therapy.” Frontiers in Endocrinology, July 9, 2019; 10:446.)

There appears to be a subset of hypothyroid patients whose unresolved symptoms when they’re prescribed just T4 has an underlying cause, something called D2 gene polymorphism. (According to Wartofsky, “[a] suggestive clue to the presence of this polymorphism could be a higher than normal free T4/free T3 ratio.”)

Yet even given mounting evidence that some hypothyroid patients may require a more tailored therapeutic approach, many doctors remain resistant to the idea of treating them with both T3 and T4.

There are a few reasons for this. First, some doctors are reluctant to embrace a therapeutic approach that deviates from what they were taught in med school. This can be frustrating for patients.

Second, the TSH tests of a person on just T4 usually look perfect, and some doctors will think: why mess with perfection? Even if a patient’s T3 is a bit low, what’s the big deal? The most important numbers is TSH, after all. Here’s the rub: most people on T4 alone have no adverse symptoms. But for those who do, how they feel is as important as what their tests show.

Unfortunately, many doctors who see “perfect” numbers will conclude that ongoing symptoms like lethargy and depression are “all in her head.” To complicate matters, thyroid imbalances can cause or worsen psychological symptoms like depression or anxiety. There is another signifcant concern: because T3 is both more metabolically active and shorter-lasting than T4, a lot of physicians worry that prescription T3 will cause an initial surge of hormone (with attendant side effects) and then a sharp drop. They fear it will be much more diffcult to predict and regulate dosages.

There are ways around this problem. Dr. Ridha Arem has encountered many patients with lingering symptoms on T4 alone despite good test results. “Treating them with T4 and T3 to duplicate how the thyroid gland naturally functions provided them with spectacular results,” he writes. He notes that the dosage needs to be adjusted individually. Because T3 is more potent, he generally decreases the amount of T4 his patients receive when T3 is added. He also adds T3 in very small amounts, and then patients get blood tests six to eight weeks after their regimens have been changed.

Dr. Arem has become a proponent of compounded T3 (made by a compounding pharmacy) precisely to address the concern of a spike in hormone followed by a sudden drop. Compounded T3, however, can be prescribed in variable dosages, and as a time-released formulation, so it doesn’t produce the same peak and plummet effect. It can thus be taken just once a day, which is far more practical. Other physicians, like Dr. Holtorf, use a similar approach with their patients.

Natural or Synthetic Hormones?

Patients speak up

“I had problems on Synthroid and switched to Armour. I am now in excellent health with lots of energy, a cheerful disposition, and greatly improved mental acuity and memory. I also found it easy to lose seven pounds, which I could not do on Synthroid.

“Armour Thyroid has both T3 and T4, whereas Synthroid provides only one of these and the body is supposed to manufacture the other. Is it possible some of us can’t make the other, so Synthroid doesn’t work for us? I am living, bouncing proof that a switch to a natural thyroid can work.”

“I was diagnosed with hypothyroidism a long time ago and prescribed Synthroid. It improved my lab numbers but never got them to normal.

“As an aside, I have been under treatment for depression for decades. A new psychiatrist recently checked my thyroid and determined that the Synthroid was not doing the job and recommended desiccated thyroid. Within a month the depression lifted, I started losing weight and am feeling better than I have in decades. Why don’t doctors prescribe desiccated thyroid more often?”

Here’s another wrinkle in the whole question of thyroid hormone for treating sluggish glands. Synthetic supplements supply either only T4 (Synthroid, Levothroid, Tirosint, etc.) or only T3 (Cytomel). Natural supplements, on the other hand—things like Armour Thyroid, Nature-throid, Westhroid, etc.—contain both T4 and T3. That’s because these medications are made from desiccated animal thyroid glands containing both active hormones.

Many patients swear by Armour Thyroid. They say that it’s what works for them. Some doctors, too, believe that natural supplements are better absorbed than synthetics, and that patients whose symptoms persist when they’re on just levothyroxine deserve a trial of desiccated thyroid.

But many doctors may get testy when the name “Armour” is mentioned. Even Dr. Arem, a big proponent of balancing T3 and T4, prefers compounded synthetics. Dr. Holtorf similarly believes that compounded T3 is likely more effective for most sick patients than Armour Thyroid is.

Dr. Arem sometimes prescribes low doses of Armour, but he notes that pig thyroid contains higher amounts of T3 than human glands. Thus even a small dose, half a grain, can make a person’s T3 levels go “up above normal for a few hours and then back down,” which means that the person’s thyroid hormone isn’t balanced. This creates problems, with muscle, bone and metabolism. For those reasons, he recommends that patients on Armour take it two to three times per day, in divided doses. Sometimes, for patients who seem like they’ll beneft, he prescribes Armour alongside synthetic T4. As he emphasizes, “each person requires a different amount of thyroid hormone on a daily basis, so the treatment protocol has to vary from one person to the other.”

Some doctors are highly skeptical of this approach, but there are also doctors who are eager to help patients custom-tailor a therapeutic treatment that will work best for them to get their thyroid hormones balanced and their symptoms under control. The trick is to find the right doctor—one with a track record of using a combined T3 and T4 approach. If a doctor hasn’t prescribed T3 in the past, Dr. Arem warns, she may, in an excess of caution, under-dose her patient, and then when nothing improves, she’ll conclude that T3 supplementation doesn’t work.

What to Do If your Thyroid Medicine Isn’t Available

Most doctors recommend against switching between thyroid medications, or even between the brand name and the generic form of a drug, as this may affect dosage. But occasionally, doctors and patients have no choice, e.g., when a thyroid drug is unavailable for some reason. For instance, the drug Levoxyl was recalled for more than a year, from early 2013 to early 2014, for an “uncharacteristic odor.”

While medications are recalled from time to time, it’s generally just one batch or one dosage. The Levoxyl recall was unusual and required many patients to switch medications, with follow-up blood work and dosage adjustments.

What happens far more often, according to health advocate Mary Shomon, is that patients are given misinformation about a drug’s availability. In her experience, this is especially true of natural thyroid medications.

Over the years, she has heard from many frustrated folks who have been told by a doctor or pharmacist that they can’t get their medications because they’re off the market or have been banned by the FDA although that’s not the case. Sometimes, patients may hear such rumors repeatedly. This may happen for a variety of reasons. (For an article she wrote on the subject, click here.)

Before accepting claims about a discontinued medication as fact, Shomon recommends the following:

  • Check Mary Shomon’s Thyroid page on About.com, or sign up for her newsletter (and/or check the People’s Pharmacy website and newsletter). If a commonly prescribed drug has actually been discontinued, you’re very likely to hear about it from one of these sources.
  • Ask your doctor or pharmacist to provide verifcation from the manufacturer confrming that your medication has, in fact, been taken off the market. You can also call the patient line of the drug company for yourself.
  • If you believe that your doctor or pharmacist is giving you misinformation, it may be time to switch to a different health care professional, or at least get a second opinion.

Thyroid Treatment and Bone Density

Hypothyroidism and Depression

Depression is one of the most common symptoms of an underactive thyroid. It’s also one of the most overlooked. Many people are put on antidepressants when in fact what they really need is thyroid medication, or an increased dose.

According to Dr. Holtorf, 80 percent of people with depression have low thyroid. He has said, too, that “the largest study ever done on antidepressants showed that giving the active thyroid hormone, T3, was a better antidepressant than antidepressants, and with fewer side effects.”

If you’ve received a depression diagnosis and have one or several other symptoms indicating hypothyroidism, it’s wise to get your thyroid tested before going on antidepressant medications, particularly as many of them are difficult to get off of and may cause nasty withdrawal symptoms. (If you’re interested in more information on depression, there is a Graedons’ Guide to Dealing with Depression as well.)

For a long time, it was thought that there were no consequences of replacing a person’s thyroid with a synthetic substitute, as long as the dose was carefully calibrated. But now it’s suspected that taking thyroid medication may increase a person’s risk of osteoporosis, especially when it’s taken at higher-than-average doses. That’s because one of the systems that the thyroid profoundly affects is bone metabolism.

Osteoporosis is a symptom of hyperthyroidism, so it would make sense that people getting too much medication might develop weakened bones. Unfortunately, even normal doses may lead to reduced bone density, for reasons that aren’t yet entirely understood. Research suggests, however, that the closer a person’s thyroid hormone levels are to a normal range, the less likely she is to suffer bone loss.

For these reasons and others, it’s very important to carefully monitor thyroid levels: to be alert to your own symptoms, communicate with your doctors, and to get blood tests at regular intervals.


Hypothyroid patients may also have high cholesterol. That’s another aspect of the condition that might be missed or mistreated.

Thyroid dysfunction doesn’t necessarily cause extremely high cholesterol but can it account for some cholesterol elevation, particularly bad cholesterol, LDL. Before prescribing cholesterol-lowering medicine, doctors ought to check thyroid function. As Dr. Kirk has pointed out, “some of the cholesterol drugs can cause more side effects—like muscle side effects and so forth—if your thyroid is underactive. There are a lot of reasons why people with cholesterol issues should have their thyroid checked.”

Thyroid & Autoimmunity: Hashimoto’s & Graves’

Foods That May Affect the Thyroid

  • Broccoli
  • Brussels sprouts
  • Cabbage
  • Cauliflower
  • Citrus fruits
  • Collard greens
  • Kale
  • Millet
  • Mustard greens
  • Peaches
  • Peanuts
  • Radishes
  • Rutabaga
  • Sorghum
  • Soy
  • Spinach
  • Turnips
  • Walnuts

These foods should be consumed in moderation. Cooking the vegetables diminishes the likelihood that they will affect the thyroid. Most studies show that such foods lead to goiters primarily when people are deficient in iodine.


Hashimoto’s thyroiditis is an autoimmune condition that affects the thyroid. If a person has it, her body will start attacking her own thyroid gland, treating it like a foreign invader. This causes inflammation that makes it very diffcult for the thyroid to function properly, and many people with Hashimoto’s eventually develop hypothyroidism. In fact, Hashimoto’s is the most common cause of underactive thyroid conditions in the U.S. (As for the cause of Hashimoto’s, this is far less clear.)

People who test positive for TPO antibodies likely have Hashimoto’s or are on their way to developing it. The presence of antibodies is a sign that the immune system isn’t working the way that it should be. (Unlike other thyroid tests, there’s no range for TPO antibodies; either you have them or you don’t.) Family history of any form of autoimmunity is a risk factor, so if any of your relatives has had any kind of autoimmune disorder, you may be more likely to develop one yourself, and according to Mary Shomon, “Hashimoto’s is one of the more common ones.”

Dr. Arem points out that people who have Hashimoto’s don’t always exhibit symptoms. Sometimes, however, they exhibit symptoms even when their hypothyroidism looks “minor,” according to blood-test results. He has said, “there is no correlation between how severe the hypothyroidism related to Hashimoto’s thyroiditis is and the symptoms and consequences for the person.” (The symptoms he refers to are the standard hypothyroidism symptoms.)

Graves’ Disease

In contrast to Hashimoto’s, Graves’ disease is an immune condition that results in an over-reactive thyroid. It’s the most common cause of hyperthyroidism. In people with Graves’, the body attacks the part of the thyroid gland that usually detects and binds to thyroid-stimulating hormone. When it fails to “see” the TSH already circulating in the body, the pituitary gland thinks that there isn’t enough of it being produced, and it starts making more and more.

We’ll address hyperthyroidism in more detail very shortly, but first, we’ll lay out some tips that Dr. Arem and Mary Shomon have offered for dietary and other lifestyle changes that may help to prevent people with Hashimoto’s from developing hypothyroidism.

Counterproductive Foods

There are some foods—including certain nutritious vegetables—that hypothyroid folks are sometimes told to avoid. Peanuts, soy and “brassica” vegetables of the cabbage family contain a chemical that may block thyroid function. Vegetables like kale, cauliflower, broccoli, cabbage, brussels sprouts, collard greens, radishes, rutabaga, and turnips are sometimes classifed as “goitrogens.” They may decrease thyroid function and perhaps even cause a goiter (an enlarged thyroid gland). The term was coined decades ago; subsequent research indicated that they are linked to goiters when they are dietary mainstays in regions of iodine defciency.

Dr. Arem suggests that people with subclinical thyroid conditions should not eat large quantities of raw cabbage-family veggies. When eaten in moderation, especially cooked, they don’t seem to cause problems. He points out that there are also other healthful foods, rich in favonoids, that should perhaps also be eaten in moderation because of the possibility that favonoids could reduce thyroid function. These foods include citrus fruits, strawberries and several others. Similarly, soy, which contains compounds that may also block thyroid function, should be consumed in moderation. More than three or four servings per week is probably too many.

Helpful Supplements and Nutrients

While there are foods and supplements that those with hypothyroidism should beware (remember to take calcium or iron at least four hours before or after thyroid medication), there are also several minerals, micronutrients, and antioxidants that are essential to the thyroid gland and that may enhance thyroid function when added to the diet in the right amounts.

Important minerals for thyroid function include copper, iron, manganese, molybdenum, selenium and zinc. Dr. Arem, Dr. Holtorf and Ms. Shomon agree that small doses of selenium can be helpful for clinical or even subclinical thyroid problems. Selenium can sometimes help lower antibodies and may help keep a person’s autoimmune response in check. Vitamins A, E, D, and B are important. Dr. Arem also recommends probiotics.

Other natural or herbal remedies that have been rumored to boost thyroid activity include the resin guggul from India, which is thought to lower cholesterol. There are currently no data, however, that it is helpful in hypothyroidism. On the other hand, there’s some evidence that seaweed, a natural source of iodine, might boost TSH to some degree. (Combet E, Ma ZF, et al, “Low-level seaweed supplementation improves iodine status in iodine-insuffcient women.” Br J Nutr. 2014 Jul 9:1-9.)

Whenever adding any new supplement, vitamin, or mineral to your diet, it’s important to consult your doctor. Too much of a good thing can sometimes be very dangerous, so it’s essential not to overdo it. (Selenium, for instance, can be toxic at high doses. Don’t exceed 50 mcg per day except under medical supervision. For zinc, the suggested dose is 15 mcg. Iodine can also be very harmful in large doses.)

Hyperactive Thyroid

Symptoms of Too Much Thyroid

  • Fatigue
  • Weakness
  • Insomnia
  • Anxiety
  • Nervousness
  • Increased blood pressure
  • Heart palpitations
  • Rapid pulse
  • Irregular heartbeat
  • Weight loss
  • Eye problems
  • Sensitivity to heat
  • Excessive sweating
  • Light menstruation
  • Irritability
  • Tremors in fingers
  • Shortness of breath
  • Frequent bowel movements
  • Diminished concentration
  • Loose or soft nails
  • Fine, soft hair
  • Hair loss
  • Increased libido
  • Increased appetite

Up until now, we’ve focused on hypothyroidism, a thyroid gland that produces too little of the hormone, which is by far the more common thyroid condition. But an overactive thyroid is just as serious.

The symptoms of hyperthyroidism, also called thyrotoxicosis, may include anxiety, insomnia and nervousness, as well as rapid heartbeat, excess sweating, sensitivity to heat, high blood pressure or wide pulse pressure, frequent bowel movements, low-flow menstrual periods or amenorrhea, and tremors in the hands. Hyperthyroid patients may also lose weight and their eyes may bulge a bit from their sockets. They may experience increased libido and appetite, shortness of breath and irritability. (While some of these symptoms may sound desirable, hyperthyroidism is very dangerous if left untreated.)

Diagnosis is confirmed by blood test. The TSH of a person with hyperthyroidism will be extremely low or even undetectable, but her T3 and T4 numbers will be elevated.

As we mentioned above, the most common cause of hyperthyroidism is Graves’ disease, an autoimmune condition. Thyroid nodules (growths on the thyroid), are another potential cause. They may be diagnosed with MRI, ultrasound, and/or CT scan.

One of the common side effects of hyperthyroidism is bone loss, so anyone diagnosed with it should have her bone density evaluated. Those with Graves’ disease should also be sure to make regular appointments with an ophthalmologist, as a very large percentage of Graves’ patients suffer from inflammation of the muscles and other tissues around the eyes. In addition to bulging eyes, other common hyperthyroid symptoms include eye redness or soreness and blurred vision.

Treating Hyperthyroidism

Preventable Tragedy

Years ago, we heard a truly tragic story from the mother of a 26-year-old woman, and we are sharing it here in the hopes of preventing a similar horror story.

The young woman was being treated with Tapazole (methimazole) for an overactive thyroid, but she wasn’t told that it could lower her white blood cell count and thus reduce her ability to fight infection.

Even though the prescribing information outlined strong warnings that doctors should tell their patients to report sore throats, fever, or other signs of infection, she was treated for many sore throats, strep infections, tonsillitis, and gingivitis, and was never once given a blood test. Her doctor simply failed to connect her series of infections with one of the very serious potential side effects of the medication she’d been prescribed to manage her Graves’ disease.

By the time she was finally admitted to the hospital with dizziness, a stomachache, vomiting, and fever, it was too late—she had a very severe infection and no remaining white blood cells with which to fight it. She died the next day.

Treating an underactive thyroid may have sounded complicated, but treating hyperactive thyroid can be even trickier. Doctors can either perform surgery, removing part or all of the thyroid gland, prescribe radiation therapy or give patients thyroid-suppressing drugs, such as Tapazole (methimazole) or propylthiouracil.

There’s no “standard treatment”—each has pros and cons and has to be tailored to specifc patients. That being said, those with Graves’ disease are often treated with radioactive iodine, which is a method that’s irreversible. Iodine concentrates in the thyroid gland. The radiation hitches a ride, and when it arrives, it destroys the gland tissue.

Because there’s no turning back with this method, it’s worth getting a second opinion before going ahead if there’s any doubt at all about the diagnosis. The same goes for surgery. (Surgery is usually recommended only in the case of thyroid cancer or certain large nodules. As with any surgery, it’s always advisable to find a surgeon with lots of experience performing the specifc procedure that you need.) With both types of treatments, patients will very often become hypothyroid afterward and will require thyroid supplementation. A third option is thyroid-suppressing medication, which is prescribed at the lowest possible doses to bring T3 and T4 into a normal range. Methimazole is more convenient, because it only has to be taken once a day. But pregnant and nursing women are generally prescribed propylthiouracil, which is taken three times a day. (Pregnant women also can’t be treated with radioactive iodine, as it may affect their babies’ thyroid glands.)

There are several possible side effects of the medicines, including a bitter taste in the mouth and nausea. (Beta-blockers are sometimes prescribed alongside thyroid drugs, to alleviate hyperthyroidism symptoms such as heart palpitations, rapid heart rate, anxiety, and tremors. But of course beta-blockers aren’t treating the underlying problem, so thyroid medications need to be continued even if some of the nasty symptoms clear up.)

Potentially serious side effects of thyroid-suppressing drugs include rash, joint pain, or elevated body temperature. If you experience any of these, get in touch with your doctor right away. Methimazole can sometimes suppress infection-fighting white blood cells, which can be very dangerous—potentially life threatening. If you come down with a sore throat or other infection, bring it to a doctor’s attention as soon as possible; if it requires an emergency visit, notify the medical team that you have hyperthyroidism and are taking a medication that could be suppressing your white blood cells.

Hyperthyroidism and Other Supplements and Drugs

Dr. Kent Holtorf believes that there are some supplements and drugs other than thyroid-suppressing medications that may help to reverse hyperthyroidism. For instance, he thinks that selenium may reduce the autoimmune antibodies that cause Graves’ disease by as much as 40 percent. (Selenium needs to be taken in small doses, as it is harmful in large doses.)

Dr. Holtorf is also a proponent of low-dose prescription naltrexone, a drug that blocks opioid receptors. (It’s sometimes used to treat alcohol dependency or pain medication overdose.) He has said that “at very low dose, it’s an immune modulator and reduces autoimmunity for a number of things, including Graves’ disease.” He acknowledges that it doesn’t work for everyone, but thinks that it works for many people; even if it doesn’t eradicate an illness, it may make it more manageable. This is an uncommon treatment, however, so many other doctors may be resistant to the idea.

Older People and Thyroid Treatment

It can sometimes be more diffcult to identify a thyroid problem in older people. Symptoms of hypothyroidism—fatigue, forgetfulness, constipation, hair loss, etc.—are often mistaken as normal signs of aging. The same may be true of symptoms of overactive thyroid such as heart palpitations, nervousness, weakness, etc.

Older people may also present symptoms that are different from those of younger adults with thyroid imbalances. For instance, in older people, too much thyroid may actually result in some hypothyroid symptoms, like decreased (not increased) appetite, depression, apathy and constipation. It may also lead to congestive heart failure, dementia and muscle rigidity. Because the symptoms may look different from “textbook” cases of thyroid disorders, doctors may not even suspect a thyroid problem.

Further complicating things, blood tests may show high TSH numbers in some older people who don’t have symptoms. Adding to the confusion, their free T4 may look normal. One study found that 15 percent of men and women over 60 have subclinical hypothyroidism.

It’s not always clear if these patients should be treated. This is controversial because it’s extremely important not to over-treat older adults; osteoporosis and heart disease could both be made worse if patients take too much thyroid medication. Older people often metabolize medication more slowly as well. It’s important that they receive the smallest possible dose needed to treat their conditions—often this dose is smaller than for younger people—and that they do necessary follow-up tests with their doctors. This is especially important if a patient already has heart disease.

Children and Thyroid

iAs important as thyroid hormone is for adults, it’s even more critical for children, as it governs growth and development. As a result, kids are routinely screened at birth for any thyroid abnormalities. About one in 4,000 babies are born without enough thyroid hormone and are given supplemental thyroxine to prevent problems.

Although it’s rare in the U.S., in places where iodine is in short supply and a mother doesn’t get enough of it while she’s pregnant, her child may develop cretinism, (congenital hypothyroidism). Symptoms include severe growth, developmental, and cognitive delays. (Babies with severe untreated hypothyroidism may lose three to five I.Q. points in their first few years.)

Kids can also develop thyroid imbalances after infancy. A change in the growth curve is one sign that a child might be developing hypothyroidism. As is true for adults, kids’ diagnoses can only be confirmed with blood tests, such as for TSH. The dosages of thyroid medications that they’ll be prescribed will be extremely small, and are often partial doses of small adult doses.

Graves’ disease is very rare in young kids, but it is possible for them to develop it. Parents often notice emotional symptoms more readily than the physical symptoms that affict adults, but kids may suffer from both. Kids with Graves’ are generally not treated with radioactive iodine, as it isn’t known what the long-term consequences may be. As a result, they’re generally treated with either very small doses of thyroid-suppressing medications or with surgery.

Thyroid Hormone for Obesity or Fatigue

In past decades, thyroid hormone was sometimes prescribed to treat obesity or chronic tiredness. Doctors are very strongly discouraged from doing this today, which is part of the reason that some doctors are wary of “alternative approaches” to thyroid treatment—they worry that medications are overprescribed for people who don’t need them, which may put their health at risk.

Sometimes, if people have access to thyroxine, they may even try to treat themselves, which is a very bad idea. The same goes for any over-the-counter products that contain desiccated animal thyroid. Several exist. Taking them without medical oversight or collaboration could result in serious adverse consequences.

The repercussions of unnecessary treatment or overtreatment can be very dangerous and even life threatening. Correcting suspected or confirmed thyroid imbalances is not a do-it-yourself project. It’s absolutely imperative that it be undertaken with the guidance and support of a knowledgeable physician.


Ain, Kenneth, MD, and Rosenthal, M. Sara, PhD. The Complete Thyroid Book. McGrawHill, 2011.

Arem, Ridha, MD. The Thyroid Solution Diet. Atria Books, 2013.

Blanchard, Kenneth R., MD. The Functional Approach to Hypothyroidism. Hatherleigh, 2012.

Bowthorpe, Janie A. Stop the Thyroid Madness II. Laughing Grape Publishing, 2014.

Shomon, Mary. The Thyroid Diet Revolution. William Morrow, 2011.


http://www.aremwellness.com Dr. Arem’s website

http://thyroid.about.com Mary Shomon’s blog

https://www.aace.com/fles/hypothyroidism_guidelines.pdf For professionals, a 45-page guide to treating hypothyroidism from the American Thyroid Association and the American Association of Clinical Endocrinologists. 2012.

http://www.nahypothyroidism.org National Academy of Hypothyroidism, Dr. Holtorf’s website


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Published on: March 11, 2024


Last Updated: June 28, 2024

Publisher: The People's Pharmacy

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