LH is a dimeric glycoprotein hormone secreted by the anterior pituitary in response to hypothalamic gonadotropin-releasing hormone (GnRH). Its α-subunit is common to other glycoprotein hormones, while its β-subunit—responsible for biological activity—shares partial homology with that of human chorionic gonadotropin (hCG).
During the menstrual cycle, FSH stimulates follicular development. When the follicle reaches maturity, ovulation occurs in response to a surge in LH (and to a lesser extent, FSH). Ovarian steroids serve as the primary negative feedback regulators of LH secretion.
At menopause, decreased ovarian steroid production leads to loss of negative feedback and a rise in LH concentrations. Elevated LH is also observed in premenopausal women with ovarian failure or incomplete ovarian maturation during puberty.
≤ –20 °C; avoid repeated freeze–thaw cycles. For short-term storage (≤8 hours), keep samples at room temperature (15–30 °C); for up to 48 hours, refrigerate at 2–8 °C.
Hemolyzed or unspun specimens (may yield inaccurate results)
Enhanced chemiluminescence.
| Category | LH (mIU/mL) |
| Female, mid-follicular phase | 2.12–10.89 |
| Female, mid-cycle peak | 19.18–103.03 |
| Female, mid-luteal phase | 1.20–12.86 |
| Postmenopausal female | 10.87–58.64 |
| Male | 1.24–8.62 |