Overnight fasting before test. Normal values depend on age and sex. Higher values during normal puberty. Insulin tolerance test Stimulation test in which a dose of insulin is given intravenously. Blood is drawn before and every 15 minutes after the insulin dose for 90 minutes.
Blood is tested for glucose, growth hormone, cortisol, and prolactin.
Iodine uptake test See below for a full description. Ionized calcium level Blood tests that measure only free calcium level. Involves rapid IV injection of LHRH, then blood sampling. Rise in LH and FSH peak at 30 to 60 minutes following injection. Response in women varies with phase of menstrual cycle.