In hypothalamic amenorrhea, which hormone level is typically normal?

• A. Prolactin
• B. FSH
• C. LH
• D. Estradiol

Answer: (A)

In hypothalamic amenorrhea the primary problem is reduced GnRH secretion from the hypothalamus, which lowers the pulse-driven release of gonadotropins from the pituitary. Because FSH and LH fall, the ovaries produce less estradiol, leading to amenorrhea and hypoestrogenism. Prolactin tends to stay within the normal range because there isn’t a disruption of dopamine’s inhibitory control or a pituitary stalk lesion driving prolactin excess in this scenario. If prolactin were elevated, that would point toward a prolactinoma or another pituitary issue rather than hypothalamic suppression. So prolactin being normal fits the typical pattern, with FSH, LH, and estradiol suppressed due to decreased GnRH drive.