What Is A Thyroid Gland? The thyroid gland is the largest gland in the endocrine system. The shape of the thyroid gland is of a butterfly and it is located in the neck. It produces 3 hormones: Thyroxine (T4), Triiodothyronine (T3) [routinely counted as thyroid hormones] and Calcitonin. Excess or lack of thyroid hormones can […]