see also:

• hormones
• thyroid physiology and hormones

• TSH is a glycoprotein hormone synthesized and secreted by thyrotrope cells in the anterior pituitary gland
• it stimulates the thyroid gland to produce thyroxine (T4), and then triiodothyronine (T3)
• high circulating levels of TSH indicate hypothyroidism whereas hyperthyroidism results in low circulating levels of TSH