Thyroid hormone (T4)

Hormone produced by the thyroid gland that acts on energy metabolism (heart rate, body temperature, and burning of food). Hypothyroidism is common in women and can easily be treated with a small daily pill containing T4. OR T4 or L-thyroxine is the major hormone released by the thyroid gland under the influence of TSH. T4 is made, within body cells, into the active hormone, T3, that is tightly controlled and protectively decreases when a person is undernourished or ill or very stressed.