What prolactin does
Prolactin is a pituitary hormone that stimulates breast milk. When it is high outside pregnancy, it can switch off the hormones that control periods, fertility and sex drive.
Symptoms
- Women: irregular or absent periods, milky discharge from the nipples, difficulty conceiving
- Men: low sex drive, erectile problems, infertility
- Both: headaches or vision changes if a large pituitary tumour is the cause, and bone thinning over time
Common causes
- Pregnancy and breastfeeding
- Stress, recent exercise or a difficult blood draw
- Medicines, including some anti-sickness, antipsychotic and antidepressant drugs
- An underactive thyroid or kidney disease
- A benign pituitary tumour (prolactinoma)
- Macroprolactin, a harmless form that some tests detect
Tests
A raised result is usually repeated at rest. Your doctor will review your medicines and check a pregnancy test, thyroid and kidney function. An MRI of the pituitary is done when prolactin stays high without another clear cause.
Treatment
Treatment depends on the cause. A prolactinoma usually responds very well to tablets called dopamine agonists, such as cabergoline. Surgery is rarely needed. If a medicine is responsible, do not stop it on your own; discuss alternatives with the doctor who prescribed it.
When to see a specialist
Consider an endocrinology opinion for a persistently raised prolactin, a pituitary finding on MRI, or symptoms with a high level.
This guide is general information and is not a substitute for a consultation.