Health condition
Prolactinoma deep dive
A prolactinoma is a benign prolactin-producing pituitary adenoma causing missed periods, milky nipple discharge, low libido and infertility - unusual among pituitary tumours in that tablets, not surgery, are the first-line treatment.
Why trust this guide
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Editorial team
Written by our editorial team from the UK sources listed on each page.
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Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
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Current for 2026
Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.
Key facts
The essentials at a glance.
The symptoms to recognise, when to seek help, which specialist to see, and what treatment usually involves.
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In women: irregular or absent periods, galactorrhoea and subfertility; in men: low libido, erectile dysfunction and low testosterone
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Large tumours can press on the optic nerves, narrowing the outer visual fields
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Diagnosis: a raised prolactin (repeated, and screened for macroprolactin), other pituitary hormones, and MRI
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Dopamine agonist tablets (cabergoline) shrink most tumours and normalise prolactin
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Surgery is reserved for resistance, intolerance or selected patients choosing it - discussed in a pituitary MDT
Understanding the condition
What it is and what happens next.
What causes it, how it is diagnosed, and the treatment routes available in the UK.
What it is and how it feels
Prolactin's job is milk production, and excess switches off the reproductive axis: cycles stop or scatter, fertility falls, libido fades and bones thin. Microprolactinomas (under 1 cm) are common, especially in women; macroprolactinomas can additionally cause headache and visual field loss by pressing on the optic chiasm. Medication-induced prolactin rises - antipsychotics especially - and other pituitary masses must be distinguished before the label is applied.
Diagnosis and treatment routes
The workup pairs repeated prolactin measurement (with macroprolactin screening to exclude a laboratory artefact) with pituitary MRI and a check of the other pituitary hormones and visual fields for larger tumours. Cabergoline normalises prolactin and shrinks the tumour in the large majority, restoring cycles and fertility; treatment is monitored and sometimes withdrawn after years of control. Most people start with their GP; NHS endocrinology waits often run 20-45+ weeks, while a private endocrinologist appointment is typically available within about two weeks.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a consultant endocrinologist. Your GP can refer you on the NHS, or you can arrange a private consultation directly.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any of the emergency symptoms described above.
Frequently asked
Common questions about Prolactinoma deep dive.
Quick, plain-English answers to what people ask us most.
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What is a prolactinoma?
A prolactinoma is the most common type of hormone-secreting pituitary tumour, producing excess prolactin, which can cause a range of hormonal symptoms affecting fertility and sexual function in both men and women.
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What causes prolactinomas?
They arise from abnormal, benign growth of prolactin-producing cells in the pituitary gland, typically occurring sporadically without a clear identifiable trigger.
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What are the symptoms?
Women often notice irregular periods and unexpected milk production, while men typically experience reduced libido and erectile dysfunction; larger tumours can additionally cause headaches or visual disturbance.
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Are prolactinomas dangerous?
Most are benign and slow-growing, with the primary concerns relating to hormonal effects on fertility and bone health, and, for larger tumours, potential pressure on the optic nerves.
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Can prolactinomas be cured with medication?
Medication is very effective, often normalising prolactin levels and shrinking the tumour substantially, and in some well-controlled cases, treatment can eventually be reduced or stopped under specialist supervision.
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How are prolactinomas treated?
Dopamine agonist medication is the standard first-line treatment and is highly effective for the vast majority of patients, with surgery reserved for those who don't respond adequately or can't tolerate medication.
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How is a prolactinoma diagnosed?
A blood test for prolactin levels, combined with pituitary MRI imaging, confirms the diagnosis, once other causes of raised prolactin, such as certain medications, have been excluded.
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How long does treatment take to work?
Many people see prolactin levels normalise and symptoms improve within a few months of starting medication, with tumour shrinkage typically confirmed on imaging within about six months.
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Prolactinoma vs a non-functioning pituitary tumour — what's the difference?
A prolactinoma actively secretes excess prolactin causing specific hormonal symptoms, while a non-functioning tumour doesn't secrete hormones and tends to cause problems mainly through its physical size; blood testing distinguishes clearly between the two.
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When should I see a specialist, and how quickly can I be seen privately?
See an endocrinologist for symptoms of raised prolactin such as menstrual changes or unexpected milk production. Private specialist assessment is typically available within about two weeks, faster than standard NHS referral pathways.