This biomarker is part of the Biolytics App. For a complete list of all available biomarkers, visit: Biomarkers.

Total T3

Aliases: Total Triiodothyronine

Group: Hormone

Description:

T3 is one of two major hormones made by the thyroid, a small, butterfly-shaped gland located near the throat. The other hormone is called thyroxine (T4). T3 and T4 work together to regulate how the body uses energy. These hormones also play an important role in controlling weight, body temperature, muscle strength, and nervous system. The T3 hormone comes in two forms: - Free T3, which does not attach to anything - Bound T3, which attaches to protein A test that measures both bound and free T3 is called a total T3 test. If T3 levels are not normal, it can be a sign of thyroid disease.