Luteinizing hormone (LH)

LH is made by your pituitary gland, a small gland located underneath the brain. LH plays an important role in sexual development and functioning. In women, LH helps control the menstrual cycle. It also triggers the release of an egg from the ovary (ovulation).

Normal value ranges may vary slightly among different laboratories. Here are normal ranges:

Men: 1.42 to 15.4 IU/L.

Women, follicular phase of menstrual cycle: 1.37 to 9 IU/L. Women, midcycle peak: 6.17 to 17.2 IU/L.

If LH levels are higher than normal when a person is not ovulating, they may be experiencing menopause. People who have high levels of luteinizing hormone may experience infertility, because the hormone directly impacts the reproductive system. In women, luteinizing hormone levels that are too high are often connected to polycystic ovary syndrome, which creates inappropriate testosterone levels.

Low levels of LH may mean you have a pituitary disorder, anorexia, malnutrition, or are under stress. If you're a man, abnormally high LH levels along with low levels of testosterone may mean that your testicles aren't responding to LH's signal to make more testosterone.