Which two hormones are mainly produced by the thyroid gland?

The thyroid gland primarily produces two key hormones: thyroxine (T4) and triiodothyronine (T3). These hormones play critical roles in regulating metabolism, energy production, and overall growth and development within the body. Thyroxine contains four iodine atoms, whereas triiodothyronine contains three. Despite being produced in different amounts, T3 is considered the more active form of the hormone, influencing almost every physiological process in the body, including heart rate, body temperature, and the metabolic rate.

The synthesis of these hormones is governed by the thyroid-stimulating hormone (TSH) released from the pituitary gland, indicating the deep connection between the thyroid and the broader endocrine system. This focus underscores the integral role of the thyroid gland in maintaining metabolic homeostasis.