What's thyroid hormone replacement therapy (THRT)?
If you suffer from a thyroid hormone deficiency, or hypothyroidism, you can encounter symptoms as varied as lack of energy, depression, constipation, weight gain, hair loss, dry skin, dry coarse hair, muscle cramps, decreased concentration, aches and pains, swelling of the legs and increased sensitivity to cold. Possible causes of hypothyroidism include a non-functioning thyroid gland, thyroid-gland damage due to surgery or radiation treatment, or a non-functioning pituitary gland.
If you suspect your thyroid isn't working as it should, your doctor can test your thyroid levels using a TSH test or T4 test, says Kent Holtorf, M.D., Medical Director of Holtorf Medical Group, which studies women's health and endocrinology. A TSH test measures your body's levels of thyroid-stimulating hormone, which helps control the thyroid gland. Your doctor may also order a T4 test, which measures the levels of the T4 hormone in the body. T4 is one of two types of thyroid hormones. The other, T3, comes from T4, so it's not commonly measured.
These tests will let your doctor know if your thyroid isn't working properly. If you do suffer from hypothyroidism, your doctor will likely put you on thyroid hormone replacement therapy (THRT), which is basically extra T4 hormones. You've got to bump those babies up.
Common synthetic THRT medications include Synthroid, Levoxyl, Levothyroid, Unithroid. The most common natural THRT medication is Armour Thyroid and is made from porcine (pig) thyroid glands.