The Ultrasensitive TSH also known as Ultrasensitive Thyroid Stimulating Hormone Test is also known as TSH or Thyrotropin test. This test measures the levels of Thyroid Stimulating Hormone (TSH) in the blood. TSH is produced by the anterior part of pituitary gland and its function is to stimulate the thyroid gland. The Ultrasensitive Thyroid Stimulating Hormone (TSH)