LH & prolactin
Also known as:
Luteinizing hormone, PRL
Pituitary tests that explain why hormones are low, and spot a common, treatable cause.
Written and reviewed by Farhan Tahir, MD · Last reviewed
VIDEO LESSON
What they measure
LH drives testosterone production in men and ovulation in women. Prolactin supports milk production; when it runs high outside pregnancy it suppresses reproductive hormones.
When they help
• Low testosterone: high LH points to the testes; low or normal LH points to the pituitary or hypothalamus
• Missed periods, galactorrhea or infertility
• Low libido with low testosterone
What raises prolactin
• Pregnancy and breastfeeding
• Medicines such as antipsychotics and metoclopramide
• Hypothyroidism and kidney disease
• Stress, nipple stimulation or a difficult blood draw
• Pituitary adenomas (prolactinomas)
Next steps
A mildly high prolactin is repeated and checked for macroprolactin, an inactive form. Persistently high levels without an obvious cause lead to a pituitary MRI. Prolactinomas usually respond well to dopamine agonists such as cabergoline.
Key studies and references
Educational content only, written and reviewed by Farhan Tahir, MD. It does not replace individual medical advice. For sudden chest pain, trouble breathing or stroke symptoms, call 911.
AT A GLANCE
Test type
Sex hormones
Also known as
Luteinizing hormone, PRL
Reviewed by
Farhan Tahir, MD
Questions about your own care?
Dr. Tahir’s team offers consults through Youthful Medicine.
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