The thyroid gland is a
small gland located in the front of your windpipe. It releases hormones
that control your metabolism, which is your body's ability to burn
calories. T3, or triiodothyronine, is one type of thyroid hormone
released from the thyroid gland. If your thyroid gland does not secrete
enough of this hormone, you may need a T3 supplement prescription.
The Thyroid
Lab
Tests Online, a website from the American Association for Clinical
Chemistry, explains that an area of the brain called the hypothalamus
creates thyrotropin-releasing hormone, or TRH, when levels of thyroid
hormone in the blood become low. This stimulates the creation of
thyroid-stimulating hormone, or TSH, from a gland below the brain called
the pituitary gland. This, in turn, stimulates the thyroid gland to
create and release thyroid hormone. The thyroid produces two types of
hormones: thyroxine, or T4, and T3. The thyroid gland produces mostly T4, which is considered the inactive form
of thyroid hormone. T3 is considered the active form of thyroid hormone
that the body uses. T4 is converted to T3 in tissues such as the liver.
How T3 Works
According
to "Mosby's Manual of Diagnostic and Laboratory Tests," T3 only makes
up 7 to 10 percent of total thyroid hormone. In addition, 70 percent of
T3 is bound to proteins called thyroxine-binding globulin and albumin.
The rest of T3 is unbound or free, which is considered the active form.
The levels of T3 and T4 are regulated by a feedback loop. Therefore,
high levels of T3 and T4 suppress the release of TRH, leading to a
suppression of TSH and consequently a suppression of thyroid hormone. On
the other hand, low levels of T3 and T4 stimulate the release of TRH,
which then stimulates the release of TSH, which then stimulates the
release of thyroid hormone.
T3 Supplements
T3
supplements are known by the generic name liothyronine and by the brand
names Cytomel and Triostat. T3 supplements increase the basal metabolic
rate, stimulate the body's utilization of oxygen and promote the
breaking down of proteins, carbohydrates and fats. Liothyronine is
absorbed into the tissues rapidly because it is not tightly bound to
proteins. In fact, 95 percent of T3 is absorbed within four hours, notes
Daily Med, a website from the U.S. National Library of Medicine.
Indications For Use
According
to Daily Med, liothyronine is used as a supplement or thyroid hormone
replacement for people with hypothyroidism, which is a condition
characterized by low levels of thyroid hormone in the body. Other
approved uses for liothyrornine include suppression of the release of
TSH from the pituitary gland, prevention or treatment of euthyroid
goiters and thyroid suppression tests to diagnose thyroid gland autonomy
or mild hyperthyroidism.
Warning
Daily
Med notes those recovering from a type of hypothyroidism known as
subacute thyroiditis should not use liothyronine. It is also
contraindicated in those with thyrotoxicosis that has not been treated,
adrenal cortical insufficiency and allergy to any of its ingredients.
According to the PubMed Health website, possible side effects of
liothyronine include nausea, vomiting, diarrhea, stomach cramps, weight
loss, increased appetite, headache, tremor, nervousness, insomnia,
irritability, sweating, fever, increased sensitivity to heat, menstrual
cycle changes and hair loss.
