thyrotropin-releasing hormone stimulation test, a thyroid function test that assesses release of thyrotropin by the pituitary gland. A bolus of thyrotropin-releasing hormone is administered, and serum concentrations of thyrotropin are assessed at intervals. If serum levels do not increase within 30 to 40 minutes, the pituitary thyrotrophs are dysfunctional. Also called thyrotropin-releasing hormone test, TRH stimulation test, TRH test.