What are the thyroid hormones?
The thyroid gland secretes two hormones: thyroxine (also called T4) and triiodothyronine (also called T3). Together, these hormones regulate your body’s metabolism. They control how quickly your body burns energy and how quickly reactions in your body happen. Your rate of metabolism affects lots of things, such as how much you weigh and how much you sleep. Thyroxine and triiodothyronine speed up the body’s metabolism, causing organs and processes in your body to work faster. The production of the thyroid hormones is controlled by another hormone called thyroid stimulating hormone (TSH). This is made by an endocrine gland in the brain called the pituitary gland.
