Thyroid System

Thyroid Balance

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.

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.