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Home > Health Library > Luteinizing Hormone (LH)
Luteinizing hormone (LH) is produced by the pituitary gland. In women, LH helps regulate the menstrual cycle and egg production (ovulation); in men, LH stimulates the production of testosterone, which plays a role in sperm production.
Women's LH levels normally vary with the phase of the menstrual cycle, rapidly increasing just before ovulation occurs. This "LH surge" is a dependable sign that a woman is in a fertile time of her cycle. Men's LH levels normally remain constant.
Abnormally high or low LH levels can be a sign of an inability to produce eggs or sperm.
Current as of: February 11, 2021
Author: Healthwise Staff
Medical Review:Sarah Marshall MD - Family Medicine & Adam Husney MD - Family Medicine & Kirtly Jones MD - Obstetrics and Gynecology
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