Thyroid Hormone Replacement - to maintain your natural balance

Approximately 200 million people worldwide have thyroid disorders, and the risk increases with age. More than half of all Australians affected by thyroid disease are unaware of their condition. Thyroid disease affects many more women than men (possibly because women need higher levels of thyroid hormones) but it has no age, gender, or ethnic barriers. Patients may have some or all of the above symptoms, but may not be diagnosed for years.

Thyroid Hormone (TH) is produced by the thyroid gland in response to the release of Thyroid Stimulating Hormone (TSH) from the pituitary gland. TH helps the body convert food into energy and heat, regulates body temperature, and impacts many other hormone systems in the body.

Symptoms of hypothyroidism may include:

• Slowed metabolism and slowed heart rate
• Cold and heat intolerance - cold hands and feet
• Fatigue
• Fluid retention - face, legs, eyelids and abdomen
• Dry skin, eyes and/or hair
• Yellowed skin
• Loss of eyebrows
• Constipation
• Headaches, migraines
• Depression, apathy and anxiety
• Irritability - low self esteem
• Low sexual desire
• Infertility
• Memory and concentration impairment
• Enlarged tongue, deep voice and swollen neck
• Premenstrual syndrome, irregular menstrual periods
• Lack of exercise tolerance
• Weight gain (especially around the stomach area)
• Hypoglycemia (low blood sugar)

TH exists in two major forms:

• Thyroxine (T4), an inactive form that is produced exclusively by the thyroid gland.
• Triiodothyronine or Liothyronine (T3), the active form of thyroid hormone. About 20 percent of T3 is produced by the thyroid gland, with the remainder produced through conversion of T4 in various tissues of the body when more T3 is needed.

Researchers have attempted to provide appropriate thyroid hormone replacement since 1892, when the Armour meat company began to provide desiccated thyroid extract (which contains both T4 and T3) from the thyroid glands of animals. Beginning in the 1970s, the use of desiccated thyroid for the treatment of primary hypothyroidism was gradually replaced by a synthetic form of T4 known as levothyroxine sodium. Physicians note that despite apparently adequate replacement therapy with levothyroxine, some hypothyroid patients remain symptomatic. Studies suggest that replacement therapy for hypothyroidism with levothyroxine alone does not always ensure normal thyroid hormone levels in all tissues, and that a combination of levothyroxine and T3 may be required for optimal thyroid replacement therapy. However, the only commercially available form of T3 for replacement therapy is synthetic liothyronine sodium in an immediate release formulation which is rapidly absorbed, may result in higher than normal T3 concentrations throughout the body, and may cause serious side effects, including heart palpitations. Research indicates there is a need for sustained-release T3 preparations in order to avoid adverse cardiac effects due to high serum T3 levels which can result if the hormone is absorbed too rapidly.

A study published in the New England Journal of Medicine reported that treatment with T4 plus T3 improved the quality of life for most hypothyroid patients. The researchers also recommended that the ideal thyroid hormone replacement program for someone without a thyroid gland, or whose thyroid gland is nearly non-functioning, should include daily T3 in sustained-release form, along with enough T4 to ensure normal levels of thyroid hormone. Partial substitution of the T4 dose with T3 improved cognitive performance, mood, physical status, and neuropsychological function in hypothyroid patients.

For more information about thyroid hormone replacement using sustained-release T3 formulations, please contact one of our compounding pharmacists.