From Wikipedia, the free encyclopedia. Thyroid-stimulating hormone (also known as thyrotropin, TSH, or hTSH for human TSH) is a pituitary hormone that stimulates the thyroid gland to produce thyroxine (T 4), and then triiodothyronine (T 3) which stimulates the metabolism of almost every tissue in the body.timulation of the receptor increases T 3 and T 4 production and secretion. Stimulating antibodies to this receptor mimic TSH and cause Graves' disease. In addition, hCG shows some cross-reactivity to the TSH receptor and therefore can stimulate production of thyroid hormones.