t4 Posts

Normal and Optimal Thyroid Levels

Part of the endocrine system, the thyroid gland plays a major role in several body processes.

It governs growth, development, and metabolism through the hormones it releases.

The two proper hormones produced in the thyroid gland, as you might be familiar with, are T3 or Triiodothyronine and T4 or Tetraiodothyronine / Thyroxin.

They are produced in the follicular epithelial cells with the help of iodine, a trace element found in seafood, kelp, and organic potatoes, to name a few.

When these hormones are under or over its usual levels, you can develop hypothyroidism, hyperthyroidism, and other thyroid-related maladies.

If the doctor suspects you to suffer from a thyroid problem, or if he wants to exclude it from his diagnosis, he will ask you to undergo thyroid tests.

These exams will check the levels of the several hormones in your blood stream. As such, it is important that you learn more about the normal and optimal levels of the following thyroid hormones in your body:

Free T4 / Free Thyroxine / FT4

Proteins attach to the hormone T4. Known as bound T4, these hormones are stored in the bloodstream and released only as and when the body needs it.

However, there are T4 hormones which are not bound to these proteins, and they are aptly called Free T4. These hormones can be utilized by tissues and organs immediately.

The Free T4 test is preferred by most physicians due to the fact that some proteins can affect the levels of Bound T4 in the body. If the levels of FT4 and the Thyroid-Stimulating Hormone test are both abnormal, this will help confirm the occurrence of a thyroid disorder.

The normal and optimal range of FT4 is 0.9 to 1.2 nanograms per deciliter, in adults aged 20 years and above. In the pediatric population, the normal levels are as follows:

Age Levels (nanograms per deciliter)
0-5 days 0.9 to 2.5
6 days to 2 months 0.9 to 2.2
3 to 11 months 0.9 to 2.0
1 to 5 years 1 to 1.8
6 to 10 years 1 to 1.7
11 to 19 years 1 to 1.6


If your levels go above the normal range of FT4 in the body, your physician might consider the following diagnoses:

  • Graves Disease
  • Thyroiditis
  • Toxic Goiter
  • Toxic Thyroid Nodules
  • Ovarian or Testicular Cancer, albeit rare

Increased FT4 is not only associated with the above illnesses, other causes include consumption of Iodine-rich foods and excessive intake of thyroid medications.

This might also occur if you have an underlying thyroid problem and have undergone a diagnostic test which utilizes a contrast dye.

Should your results yield lower than the normal FT4 levels, your doctor will diagnose you with Hypothyroidism (i.e. Hashimoto’s Disease.) This is upon exclusion of the other causes of low FT4 levels, which occurs in the state of severe acute illness, malnutrition or fasting, or with the intake of various medications.

Deranges in FT4 levels can also occur with dysalbuminemic hyperthyroxinemia, immunotherapy, and procedures utilizing immunoglobulins or its fragments.

Total T4 / Serum Thyroxine

As it has been mentioned, there are two types of T4 hormones in the body: free and bound. Both of these hormones are measured in the Total T4 (TT4) test. Physicians employ this blood exam to check the patient’s response to hyperthyroidism treatment.

The normal and optimal values of TT4 in adults aged 20 years and above are 4.5 to 11.7 micrograms per deciliter. In pediatric patients, the normal measurements are the following:

Age Levels (micrograms per deciliter)
0-5 days 5 to 18.5
6 days to 2 months 5.4 to 17
3 to 11 months 5.7 to 16
1 to 5 years 6 to 14.7
6 to 10 years 6 to 13.8
11 to 19 years 5.9 to 13.2


A decrease in TT4 levels comes with the following conditions:

  • Hypothyroidism
  • Myxedema
  • Cretinism
  • Chronic or Subacute Thyroiditis

Low TT4 levels are also common in patients being treated with anabolic steroids or in those suffering from nephrosis.

An increase in TT4 levels often signifies hyperthyroidism or acute thyroiditis. However, pregnant women or those taking estrogen medications also exhibit high TT4 levels.

Hyperthyroidism in pregnant women is only definitive following an increase in TT4 and resin T3 uptake, according to Soldin in his 2006 study.

In light of that, diagnoses with TT4 only are not definitive as your physician will need to correlate it with the results of your other thyroid function tests.

Free T3 (FT3)

This exam is prescribed by the doctor to determine the patient’s true thyroid status, as biologically-active FT3 hormones represent a mere 0.5% of the body’s total T3 hormones. It confirms diagnosis of hyperthyroidism in conjunction with T4 and Total T3 assays. It also helps monitor an individual’s response to thyroid hormone replacement.

The normal and optimal levels of FT3 are 2.8 to 4.4 picograms per milliliter. Elevations in such foretell FT3 thyrotoxicosis especially if they are seen with normal FT4 and TT3, and subnormal levels of TSH, according to a study by Figge et al. Too much intake of thyroid hormone replacement can also increase FT3 levels in the body.

Total T3 / Serum Triiodothyronine

The TT3 exam is requested by doctors to confirm hyperthyroidism in patients with normal thyroxine and low TSH levels. It is also employed in the diagnosis of triiodothyronine toxicosis. The normal and optimal levels for people aged 20 years old and above are 80 to 200 nanograms per deciliter. As for children and young adults, the appropriate ranges are as follows:

Age Levels (nanograms per deciliter)
0-5 days 73 to 288
6 days to 2 months 80 to 275
3 to 11 months 86 to 265
1 to 5 years 92 to 248
6 to 10 years 93 to 231
11 to 19 years 91 to 218


Elevations in T3 and T4 levels confirm hyperthyroidism. However, a TT3 exam is deemed to be a better test for diagnosing hyperthyroidism as T3 levels increase before T4 levels rise.

There are also hyperthyroid individuals who only have TT3 elevations, normal T4, and TSH suppression, as is the case of T3 Thyroxicosis.

Low levels of both T3 and T4 occur in hypothyroidism, although sick or euthyroid patients admitted in hospitals also exhibit decreased T3 levels.

Starvation, as well as intake of Inderal, steroids, amiodarone, salicylates, phenytoin and phenylbutazone can also lead to low TT3 levels.

Thyroid Stimulating Hormone (TSH)

A good indicator of thyroid status, this exam determines the levels of TSH in the body. TSH is important in thyroid function as it stimulates the gland’s growth as well as the production of hormones.

The TSH exam is also done for the following purposes:

  • monitor the patient’s response to hormone replacement therapy
  • confirm suppression of TSH release in thyroid cancer patients receiving thyroxine suppressive treatments
  • predict the onset of thyrotropin-releasing hormone-stimulated TSH response

For adults aged 20 years old and above, the normal TSH levels are 0.3 to 4.2 milli-international units per liter. In children, the optimal ranges are as follows:

Age Levels (milli-international units per liter)
0-5 days 0.7 to 15.2
6 days to 2 months 0.7 to 11
3 to 11 months 0.7 to 8.4
1 to 5 years 0.7 to 6
6 to 10 years 0.6 to 4.8
11 to 19 years 0.5 to 4.3


Increased levels of TSH in the body oftentimes determine hypothyroidism. This is due to the pituitary gland’s efforts of releasing TSH in your blood in order to cope up with your underactive thyroid gland.

TSH levels are important for distinguishing primary from secondary and tertiary hypothyroidism. Rates are increased in primary hypothyroidism, while the concentration is normal to low in the latter two.

Decreased levels of TSH, on the other hand, diagnose hyperthyroidism. Since the thyroid gland produces an excess of hormones, the pituitary gland compensates by stopping the creation and release of TSH in the body.

Do note that transient or falsely low TSH levels can occur in individuals who are sick or hospitalized.

Abnormal TSH results will oftentimes necessitate other thyroid exams, such as the ones stated above, to accurately confirm the diagnosis of hyper- or hypothyroidism.

Anti-Thyroid Antibodies / Autoantibodies (TAB)

Two antibodies are checked in this exam, namely the thyroglobulin and thyroperoxidase antibodies. The normal values are <4.0 and <9.0 international units for these antibodies respectively.

Thyroglobulin antibodies, which are pivotal in the storage, release, and synthesis of thyroid hormones, are normally not seen in the circulation. They are leaked, however, in the occurrence of any of the following conditions: Graves disease, Hashimoto’s disease, neonatal hypothyroidism, postpartum thyroiditis, and autoimmune thyroid illnesses. The TAB exam is also used to measure the degree of treatment in individuals with follicular cell-derived thyroid carcinomas.

Thyroperoxidase (TPO) antibodies are also essential for thyroid hormone synthesis, and are activated following thyroid dysfunction. It is utilized to distinguish thyroid autoimmune conditions from hypothyroidism or non-autoimmune goiter. It is also used to determine the need for treatment of a patient manifesting signs and symptoms of subclinical hypothyroidism.

According to a 2010 study by Zelaya et al, TPO measurement is also beneficial for individuals with normal to high TSH levels, as they can be at risk of developing hypothyroidism in the future.

Thyroid Binding Globulin (TBG)

In persons with no signs or symptoms of thyroid dysfunction but with low levels of thyroid hormone levels, the TBG exam is warranted. The normal and optimal levels are 12-26 micrograms per milliliter in men, and 11 to 27 micrograms per milliliter in women.

Elevated levels are found in persons who are taking contraceptive steroids/estrogen or women who are pregnant. Increases in TBG can go as high as 2 to 3 fold with estrogen, according to a study by Ain et al.

Low levels, on the other hand, occur with ailments such as liver disease, nephrotic syndrome and hypoproteinemia. It also occurs in people who use glucocorticoids, androgenic, or anabolic steroids excessively.

Thyroglobulin (TG)

TG determines thyroid tissue function. It is recommended in individuals with thyroid cancer patients to see if there is residual thyroid tissue, or if the cancer has recurred or metastasized following surgery or radiotherapy.

In patients with intact thyroid tissues, the normal levels should be below or equal to 33 nanograms per milliliter. For those devoid of thyroid tissue, the levels should be below 0.1 nanograms per milliliter. For these people, a finding of 10 nanograms per milliliter or more signify residual or recurring disease.

More Info Regarding Thyroid Function Tests

As with other laboratory exams, thyroid function tests involve the extraction of blood; approximately 0.5 to 1 ml of blood will be drawn from your arm. While it is a routine procedure, it still comes with minor risks, such as bleeding or lightheadedness. In some cases, an infection or a hematoma might develop following the blood extraction process.

Should your doctor ask you to undergo FT3, TT3, FT4, TT4, TAB, or TG testing, you need to avoid taking pills containing Vitamin B7 or Biotin 12 hours prior to the procedure.

You need to inform your physician if you are taking dextrothyroxine or other drugs that lower lipid levels in the body. Such medications can interfere with the results. You will need to stop taking these drugs for 4 to 6 weeks in order to obtain accurate FT4 or TT4 results.

Exposure to animal antigens and thyroid hormone autoantibodies can also yield false FT3, TT3, TT4, or TSH results. Again, inform your physician about your clinical history so that accurate thyroid hormone measurements can be done.


Ain, K. B., Refetoff, S., Same, D. H., & Murata, Y. (1988). Effect of estrogen on the synthesis and secretion of thyroxine-binding globulin by a human hepatoma cell line, Hep G2. Journal of Molecular Endocrinology,2(4), 313-323. Retrieved August 30, 2017, from https://www.ncbi.nlm.nih.gov/pubmed/2837662.

Burch, H., MD. (2017, May). Thyroid Tests. Retrieved August 30, 2017, from https://www.niddk.nih.gov/health-information/diagnostic-tests/thyroid

Figge, J., Leinung, M., Goodman, A. D., Izquierdo, R., Mydosh, T., Gates, S., Line, B., Lee, D. W. (1994). The clinical evaluation of patients with subclinical hyperthyroidism and free triiodothyronine (free T3) toxicosis. [Abstract]. American Journal of Medicine, 96(3), 229-234. Retrieved August 30, 2017, from https://www.ncbi.nlm.nih.gov/pubmed/8154510.

How does the thyroid work? (2015, January 7). Retrieved August 30, 2017, from https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0072572/

Soldin, O. P. (2006). Thyroid Function Testing in Pregnancy and Thyroid Disease: Trimester-specific Reference IntervalsTherapeutic Drug Monitoring28(1), 8–11.

T3 (Triiodothyronine), Free, Serum. (2017). Retrieved August 30, 2017, from http://www.mayomedicallaboratories.com/test-catalog/Specimen/9404

Thyroglobulin, Tumor Marker, Serum. (2017). Retrieved August 30, 2017, from http://www.mayomedicallaboratories.com/test-catalog/Clinical and Interpretive/62800

Thyroid Function Tests. (2017). Retrieved August 30, 2017, from https://www.auburn.edu/~deruija/endo_thyroidfts.pdf

Thyroid-Stimulating Hormone-Sensitive (s-TSH), Serum. (2017). Retrieved August 30, 2017, from http://www.mayomedicallaboratories.com/test-catalog/Clinical and Interpretive/8939

Thyroxine-Binding Globulin (TBG), Serum. (2017). Retrieved August 30, 2017, from http://www.mayomedicallaboratories.com/test-catalog/Clinical and Interpretive/9263

Wisse, B. (2016, February 3). Free T4 Test. Retrieved August 30, 2017, from  https://medlineplus.gov/ency/article/003517.htm

Zelaya , A. S., Stotts, A., Nader, S., & Moreno, C. A. (2010). Antithyroid peroxidase antibodies in patients with high normal range thyroid stimulating hormone. [Abstract]. Journal of Family Medicine, 42(2), 111-115. Retrieved August 30, 2017, from https://www.ncbi.nlm.nih.gov/pubmed/20135568.

WP Thyroid

WP Thyroid, also known as Natural Desiccated Thyroid, is a natural form of thyroid hormone.

It is made from porcine thyroid glands, which contain the more potent hormone T3 Liothyronine.

It is used in the treatment of several illnesses such as thyroid deficiency and cancer, to name a few.

To learn more about WP Thyroid, from its uses to its side effects – make sure to read on below:

How WP Thyroid Works

WP Thyroid’s primary active compound is T3 or triiodothyronine, and its onset occurs within three hours after intake.

It works by providing thyroid hormones, which are naturally created by the thyroid glands, that is if you do not suffer from hypothyroidism or other related maladies.

The said hormone is essential for numerous body mechanisms, as they help in cognition, protein and fat metabolism, gastrointestinal movement, gland secretion, growth and development, to name a few.

In cases where there are low levels of thyroid hormones, symptoms such as fatigue, headache, muscle aches, constipation, and depression, can occur.

Uses of WP Thyroid

WP Thyroid is prescribed to individuals with the following ailments:

  1. Most cases of hypothyroidism, such as primary hypothyroidism due to the absence or shrinkage of the thyroid gland, or such stemming from the effects of medication and surgery. Pituitary or Hypothalamic Hypothyroidism, as well as Pregnancy-related Hypothyroidism, Cretinism and Myxedema are indications for WP Thyroid use as well.
  2. Euthyroid Goiters cases, such as Multinodular Goiter, Thyroid Nodules, Subacute and Chronic Lymphocytic Thyroiditis or Hashimoto’s Disease
  3. Thyroid Cancer
  4. Infertility due to low thyroid hormone levels

WP Thyroid is also utilized as a diagnostic agent, especially in cases where suppression tests must be done to determine mild hyperthyroidism from normal thyroid gland anatomy.

Keep in mind that the use of WP Thyroid is CONTRAINDICATED in people suffering from untreated thyrotoxicosis, adrenal cortical insufficiency, and subacute hypothyroidism, which occurs following recovery from subacute thyroiditis.

Dosage of WP Thyroid

WP Thyroid tablets come in the following dosage forms in milligrams: 16.25, 32.5, 48.75, 65 (scored), 81.25, 97.5, 113.75, and 130 (scored.)


Hypothyroidism treatment usually starts at low dosages, primarily depending on your cardiovascular health.

The initial dose usually starts at 32.5 mg, however, those with heart problems are initiated at a lower dose of 16.25 mg per day.

The dosage can be increased with an additional 16.25 mg after two or three weeks.

Gradual increments can help you meet the maintenance dose of 65-130 mg per day, which should help you attain normal serum T3 and T4 levels.

For the treatment of patients with papillary or follicular cancer of the thyroid, doses exceeding those mentioned above are warranted in order to prevent further growth of the malignant mass.


In pediatric patients, dosage will depend on the child’s age and body weight.

Careful administration of WP Thyroid in infants is important as excessive doses can lead to craniosynostosis or the premature fusion of fibrous sutures, which then alters the growth of the baby’s skull.

With that being said, the proper treatment range for children, as recommended by the American Thyroid Association and the American Association of Clinical Endocrinologists, are as follows:

Age Dose (mg) per day
0 – 6 months 16.25 to 32.5
6-12 months 32.5 to 48.75
1-5 years 48.75 to 65
6-12 years 65 to 97.5
12 years and above > 97.5


Dosage Pointers and Other Reminders

WP Thyroid tablets should be taken by mouth daily or at the frequency prescribed by the doctor.

The hormone is absorbed by the body through the gastrointestinal tract, therefore an empty stomach improves drug absorption.

For optimal results, it should be taken 30 minutes to an hour prior to eating.

Should you forget your dose, take WP Thyroid immediately once you remember it.

You should, however, skip the missed dose if the next dosage is almost due. For your safety’s sake, avoid double-dosing!

To maintain the potency of WP Thyroid tablets, they should be stored in light and moisture-resistant containers at temperatures ranging from 59 to 86 Fahrenheit or 15 to 30 Celsius.

Within four to eight weeks of therapy, the physician will require you to undergo a slew of laboratory exams, including serum T4 and TSH.

This will guide him in increasing or decreasing your dosage as necessary.

Ongoing monitoring is necessary throughout the course of WP Thyroid therapy; remember that you will be required to undergo thyroid blood testing six months after dose determination as well as a year thereafter.

Side Effects of WP Thyroid

As with any other medication, WP Thyroid comes with mild to severe side effects, such as headaches, nausea, vomiting, diarrhea, appetite changes and weight loss, sleep problems, and menstrual changes in women.

Take note that older people can be more sensitive to some side effects, such as irregular heartbeats and chest pain.

Children and adults alike can suffer from hair loss during the first few months of treatment, as this is one of the way your body adjusts with the drug.

It is usually temporary, however, if it persists, consult with your physician.

Since WP Thyroid replenishes the body with thyroid hormones, symptoms of increased thyroid levels can occur, although it is very unlikely.

However, you need to inform your doctor if you experience any of the following:

  • Tiredness or Shortness of breath
  • Sensitivity to heat or increased sweating
  • Mood swings or nervousness
  • Tremors
  • Diarrhea

Rare, life-threatening side effects can take place as well.

Should you experience irregular heartbeats, chest pain, seizures and swollen extremities, contact your physician right away.

A serious allergic reaction to WP Thyroid can also occur, again with the instances being very rare.

However, you need to inform your doctor if you experience any of the following symptoms:

  • Breathing difficulties
  • Itchiness and swollenness of the throat, tongue, or face
  • Itchiness and rashes in other parts of the body
  • Dizziness

Myxedema Coma, a rare form of severe hypothyroidism, can happen in patients who have systemic illnesses or have undergone iodine treatment, among other aggravating factors.

Symptoms includes low body temperature, psychiatric conditions (amnesia, depression, hallucination, disorientation), and uncoordinated movements of the extremities, to name a few.

Considered a medical emergency, Myxedema Coma symptoms should be referred to the physician right away.

WP Thyroid Interactions

Drug Interactions

WP Thyroid, like other medications, can interact with some of the drugs you are presently taking.

If you have diabetes, taking WP Thyroid can intensify your symptoms, as such as you need your physician to adjust your medication dosage accordingly.

In a 2014 study by Kalra, Unnikrishnan, and Sahay, it was determined that there is a need to increase anti-diabetic medication dosage for individuals with improving thyroid status, while those worsening (even with treatment) need a decrease in dosage.

Sensitivity to Anticoagulants or Blood Thinners such as Warfarin is increased in cases of Hypothyroidism.

If you are taking this drug, you will need to undergo Prothrombin time determinations so your doctor can properly adjust the dosage.

If you are taking Cholestyramine or Colestipol, you should take WP Thyroid four to five hours after as the aforementioned drug can impair hormone absorption.

Birth control pills and other medications containing Estrogen can reduce WP Thyroid hormone absorption as well, as such the latter’s dosage has to be increased if you decide to take contraceptives.

Since thyroid hormone is absorbed through the gastrointestinal tract, intake of antacids can decrease the body’s uptake of the former.

If you need to take antacids, ingest it four hours prior or after taking WP Thyroid.

Other drugs that can interact with WP Thyroid, and therefore should be used cautiously, include the following:

  • Anesthetic agents i.e. Ketamine, Phenobarbital
  • “Appetite” drugs/herbal medications
  • Calcium
  • Corticosteroids
  • Digoxin
  • Flu Medications
  • Iron Supplements
  • Multivitamins with Minerals
  • Neuro-Psychiatric drugs i.e. Carbamazepine, Phenytoin
  • Nutritional supplements i.e. Ensure
  • Respiratory Aide Medications
  • Rifabutin
  • Rifampin
  • Salicylates i.e. Pepto-Bismol, Trilisate
  • Soy Isoflavones
  • Sucralfate
  • Theophylline
  • Other Thyroid Medications

Food Interactions

While you can eat all the food you want while undergoing WP Thyroid treatment, there are those which can decrease the absorption of the drug.

As such, consumption of dietary fiber, calcium-laden food and beverages, cotton seed meal, walnuts, and soybean flour should be avoided hours before and after drug intake to maintain its ideal therapeutic levels.

The same principle applies if you are having tube feedings, especially if the regimen has lasted for more than a week.

Tube feeding should be stopped an hour prior and after drug administration for the optimal absorption of WP Thyroid.

Things to Remember Before Taking WP Thyroid

Since WP Thyroid provides supplementation for low levels of thyroid hormones, it is imperative that you narrate your full medical history to the doctor before you take the drug.

Conditions that you have that you need to disclose include diabetes, hypertension, heart problems, thyrotoxicosis, or impaired adrenal gland functioning as they can affect drug activity in your body.

As it was mentioned, a rare allergic reaction can occur with the intake of WP Thyroid. As such, it is important that you tell your physician if you have existing allergies to pork or other products.

If you are pregnant or breastfeeding, you can still take this medication for your thyroid condition. However, you should inform your doctor regarding your condition so he could fine-tune the dosage accordingly.

In most cases, some individuals need to be medicated with WP Thyroid for their entire life.

If you are one of these individuals, avoid shuffling from one brand name to another.

Most importantly, do NOT discontinue taking this medicine, even if you feel well, unless you were advised by your physician.

Controversies Surrounding WP Thyroid Use

Obesity Treatment

Since thyroid drugs such as WP Thyroid can bring about anorexia or loss of appetite, it is being utilized, alongside other medications, in the treatment of obesity.

However, it is important to note that normal doses do not bring about weight loss, and increasing dosages can even result in life-threatening events.

In a 2009 study conducted by Kaptein, Beale, and Chan, results showed that “available data are inconclusive regarding effectiveness of thyroid hormone therapy in treating obesity.” It was also postulated that it only results in subclinical hyperthyroidism, with increased appetite possibly occurring as a mild symptom.

As such, it is deemed ineffective to utilize WP Thyroid for obesity or other conditions outside its intended use.

Breast Cancer Link

Another issue linked with thyroid hormone use is breast cancer.

The association between the two has not yet been confirmed, and the study made by Bogardus and Finley showed that thyroid function impairment indeed might affect the mammary gland to some degree.

The researchers, however, suggest that “a study of the phylogenetic relationship of hormone development to neoplasia” is further needed.

Sharing the same sentiment is Dr. Mallika Marshall of the Harvard Health Blog, who said that “the effect of thyroid hormone on breast cancer risk clearly requires further study.”

For now, Dr. Marshall advises women with overactive thyroid to communicate with their doctors and follow routine breast cancer screening recommendations.

There are some other controversies regarding the general use of natural desiccated thyroid treatments that we will talk about later.


WP Thyroid treats a handful of conditions, from Hypothyroidism to Thyroid Cancer.

While effective, the drug should be taken cautiously – so make sure to follow the pointers above to keep yourself safe throughout the course of therapy.


Bogardus, G., & Finley, J. (1961). Breast cancer and thyroid disease. Surgery,49(4), 461-468. Retrieved August 3, 2017, from http://www.surgjournal.com/article/0039-6060(61)90088-5/fulltext#article-footnote-☆

Gwiezdzinka, J., & Wartofsky, L. (2012). Thyroid Emergencies. Retrieved August 3, 2017, from https://www.ccm.pitt.edu/sites/default/files/ebm/thyroid_emergencies_review_2012.pdf

Hypothyroidism. (2017). Retrieved August 3, 2017, from http://www.umm.edu/health/medical/reports/articles/hypothyroidism

Kalra, S., Unnikrishnan, A. G., & Sahay, R. (2014). The hypoglycemic side of hypothyroidism. Indian Journal of Endocrinology and Metabolism,18(1), 1-3. Retrieved August 3, 2017, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3968713/.

Kaptein, E. M., Beale, E., & Chan, L. S. (2009). Thyroid hormone therapy for obesity and nonthyroidal illnesses: a systematic review. J Clin Endocrinol Metab,94(10), 3663-3675. Retrieved August 3, 2017, from https://www.ncbi.nlm.nih.gov/pubmed/19737920.

Marshall, M. (2016, April 7). Thyroid disease and breast cancer: Is there a link? [Web log post]. Retrieved August 3, 2017, from http://www.health.harvard.edu/blog/is-there-a-link-between-thyroid-disease-and-breast-cancer-risk-201604079407

Nowak, F. V. (2009, August 25). The Thyroid Gland: Function and Regulation. Retrieved August 3, 2017, from http://www.ohio.edu/people/witmerl/Downloads/2009-08-25_Nowak_Thyroid.pdf

Thyroid Basics. (n.d.). Nature Throid. Retrieved August 03, 2017, from https://thyroidbasics.com/nature-throid/

WP Thyroid. (2017). Retrieved August 3, 2017, from https://www.drugs.com/mtm/wp-thyroid.html

WP Thyroid (thyroid) – Full Prescribing Information. (2017). Retrieved August 3, 2017, from http://www.pdr.net/full-prescribing-information/WP-Thyroid-thyroid-3202

WP Thyroid Oral : Uses, Side Effects, Interactions, Pictures, Warnings & Dosing. (2017). Retrieved August 3, 2017, from http://www.webmd.com/drugs/2/drug-164877/wp-thyroid-oral/details

WP Thyroid. (2017). Retrieved August 3, 2017, from https://www.goodrx.com/wp-thyroid/side-effects