Prolactin is best known for its role in milk production, but it also affects periods, fertility and libido. It is part of the female Hormone Profile in the screen.
Prolactin. A hormone made by the pituitary gland at the base of the brain. It drives milk production after birth and, when raised, can quieten the hormones that run the menstrual cycle.
Outside pregnancy and breastfeeding, prolactin is normally kept low. When it rises, it can damp down the signals from the brain to the ovaries. That is why a raised level is often linked with irregular or missed periods, difficulty conceiving, lower libido and, sometimes, a milky discharge from the nipples. Checking prolactin alongside thyroid and the rest of the Hormone Profile helps make sense of cycle changes.
Prolactin is also one of the most easily disturbed hormones in the blood. Stress, a poor night's sleep, a hard workout, nipple stimulation and even the draw itself can push it up for a while. It is naturally higher during sleep and in the first hours after waking. A single high reading is therefore often repeated before anyone reads too much into it.
Labs report prolactin in ng/mL or mIU/L. As a rough guide, 1 ng/mL is about 21 mIU/L. Reference ranges vary by lab and are different for women and men, so read your result against the range on your own report.
A mildly raised result is commonly linked with stress, poor sleep, the timing of the draw, an underactive thyroid or some medicines. Some people carry a large, inactive form of prolactin that reads high but causes no symptoms. A clearly or persistently high level is a reason to speak to your own doctor.
A low prolactin is uncommon and usually of little concern on its own. Very rarely it reflects a problem with the pituitary gland, which is read alongside your other hormones.
Reference ranges differ between labs, and a single result is a snapshot. Your consultant reads every value against your history and the rest of the screen, not in isolation.
This test is part of Baseline’s full blood screen: 122 parameters across ten systems from one draw, for AED 850, with results in 48 hours. It is not sold as a single test, because the result means more next to everything else.
Ranges are the lab’s own. Your consultant goes through what they mean with you.
Your results arrive in the Baseline app, every marker against the lab’s own range, checked by your consultant before you see them. The values above are an example.
This page is general information, not a diagnosis. If you feel unwell, or your symptoms are new or getting worse, speak to a doctor.
Reading is not a diagnosis. A consultation goes through your history with you and tells you plainly whether a program fits, including when it does not. AED 350, credited in full against your first order.