WHAT IS A THYROID GLAND? The thyroid is located in front of the neck. It is produces hormones that control your metabolism and your weight. It makes two thyroid hormones called T3 (triiodothyronine) and T4 (thyroxine). These hormones ensure that your metabolism, weight, and mood, among many other body systems are working well. When these hormones are out of balance and when the thyroid is not active enough, it is known as hypothyroidism. [...]