The butterfly-shaped thyroid gland is located in the front of your neck and wraps partially around the windpipe. The gland is responsible for making thyroid hormones that control the metabolism of all cells in your body.
If the thyroid overproduces hormones, you can have a condition called hyperthyroidism. This condition commonly causes symptoms such as a forceful and rapid heart beat, insomnia, sudden weight loss, breathlessness, nervousness, irritability, sweating, and frequent bowel movements.1
Many people can also suffer from different degrees of low or underactive thyroid function, called hypothyroidism. Symptoms of a thyroid gland producing too little thyroid hormone can include a slow metabolism, listlessness, lowered body temperature, weight gain, constipation, muscle soreness, feeling cold, fatigue, depression, high cholesterol and homocysteine, painful joints, dry skin, and hair loss.1-4
There are two types of thyroid hormones: Thyroxine (T4) and Triiodothyronine (T3). T4 is inactive and kept in reserve; T3 is the active hormone. Thyroid hormones control the growth, differentiation, and metabolism of each cell in our body. They also control how fast our body uses the fuel that we consume, particularly carbohydrates and fat.1 This helps to regulate our body temperature and fat percentage. About 80% of thyroid hormone production is T4, the inactive thyroid hormone that is typically held in reserve by the body. T3 makes up only 20% of thyroid hormone production,5 but it is the active hormone that the body uses to function. T4 is converted into T3 when thyroid hormone is needed.
The release of the thyroid hormones is controlled by the thyroid stimulating hormone (TSH), which is produced in the pituitary gland. Low circulating levels of thyroid hormone are detected by the hypothalamus, which then instructs the pituitary to release TSH. When sufficient amounts are released, the hypothalamus communicates with the pituitary to stop or slow down. Because of this complicated feedback loop, high levels of TSH in the blood often mean the pituitary is trying to stimulate thyroid hormone production, but the thyroid gland is not responding. This condition is known as hypothyroidism.
Benefits of Thyroid
- Regulates temperature, metabolism, and cerebral function
- Increases energy, body temperature, and warmth
- Increases fat breakdown, resulting in decreased weight and lower cholesterol2
- Protects against cardiovascular ailments3,6
- Improves cerebral metabolism
- Supports cognitive function7
- Relieves symptoms of thin sparse hair, dry skin, and brittle nails
The most common side effects from too high a dose of thyroid hormone are heart palpitations,8 increased pulse, excessive sweating, heat intolerance, and nervousness.
The recommended form of thyroid replacement is an Armour Thyroid Compound, which is a combination of T3 and T4.9 Studies show that a percentage of patients prefer the combination of T4 and T3 over T4 alone.10,11 The combination allows the body to receive the active and inactive form to treat those patients who are not able to properly convert. In contrast, traditional physicians continue to prescribe the synthetic thyroid hormone T4 or Synthroid. Synthroid is only T4 and may not convert to T3.
- Huber MA, Terézhalmy GT. Risk stratification and dental management of the patient with thyroid dysfunction. Quintessence Int. 2008 Feb;39(2):139-50.
- Asranna A, et al. Dyslipidemia in subclinical hypothyroidism and the effect of thyroxine on lipid profile. Indian J Endocrinol Metab. 2012 Dec;16(Suppl 2):S347-9.
- Kutluturk F, et al. Changes in metabolic and cardiovascular risk factors before and after treatment in overt hypothyroidism. Med Glas (Zenica). 2013 Aug;10(2):348-53.
- Rao ML, et al. Low plasma thyroid indices of depressed patients are attenuated by antidepressant drugs and influence treatment outcome. Pharmacopsychiatry. 1996 Sep;29(5):180-6.
- Sapin R, Schlienger JL. [Thyroxine (T4) and tri-iodothyronine (T3)determinations: techniques and value in the assessment of thyroid function]. Ann Biol Clin (Paris). 2003 Jul-Aug;61(4):411-20.
- Klein I, Ojamaa K. Thyroid hormone and the cardiovascular system. N Engl J Med.2001;344(7): 501-509.
- Bunevicius R, et al. Effects of thyroxine as compared with thyroxine plus triiodothyronine in patients with hypothyroidism. N Engl J Med. 1999 Feb 11;340(6):424-9.
- Toft AD. Thyroid hormone replacement – one or two? N Engl J Med. 1999 Feb 11;340(6):469-70.
- Gaby AR. Sub-laboratory hypothyroidism and the empirical use of Armour thyroid. Altern Med Rev. 2004 Jun; 9(2):157-179.
- Escobar-Morreale HF, et al. Thyroid hormone replacement therapy in primary hypothyroidism: a randomized trial comparing L-thyroxine plus liothyronine with L-thyroxine alone. Ann Intern Med. 2005 Mar 15;142(6):412-24.
- Sesmilo G, et al. Serum free triiodothyronine (T3) to free thyroxine (T4) ratio in treated central hypothyroidism compared with primary hypothyroidism and euthyroidism.Endocrinol Nutr. 2011 Jan;58(1):9-15.