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Health condition · Clinically reviewed

Galactorrhoea, prolactin, medications and the pituitary.

Milky nipple discharge outside pregnancy is common, treatable and usually explained by a raised prolactin. A careful medication review and the right tests find the cause quickly.

Jump to treatment
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Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Checked against Endocrine Society, Society for Endocrinology and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK practice, including prolactin interpretation, medication review and pituitary MDT referral.

Key facts

Galactorrhoea at a glance.

The essentials, in plain English, what causes it, how it is investigated, and when it needs specialist input.

  • What it is

    Milk-like nipple discharge outside of pregnancy and breastfeeding, from one or both breasts.

  • Common driver

    Hyperprolactinaemia, most often from medications, hypothyroidism, a prolactinoma or stalk-effect pituitary lesions.

  • Not always sinister

    Truly bilateral, milky and expressible discharge is usually benign, but warrants a proper endocrine work-up.

  • Different from

    Bloody, serous or purulent nipple discharge, which points to breast rather than pituitary pathology.

  • Foundation tests

    Fasting morning prolactin, TSH and free T4, pregnancy test, U and Es, LFTs and a careful medication review.

  • When to escalate

    Persistently high prolactin without a medication cause, visual field defects, headaches or menstrual disturbance.

Why this guide matters

A structured approach beats guesswork.

Galactorrhoea deserves a careful, methodical work-up. The three points below shape everything else on this page.

  • Prolactin is the pivot

    A fasting morning prolactin, checked with a macroprolactin screen where needed, guides every next decision.

  • Medications first, imaging later

    Antipsychotics, antiemetics and several other drugs raise prolactin. A rigorous medication review often removes the need for a scan.

  • Prolactinoma is treatable

    Dopamine agonists such as cabergoline shrink most prolactinomas and restore fertility, so surgery is rarely needed.

How the diagnosis is made

From first discharge to a clear plan.

The steps a UK GP or endocrinologist will normally follow, in order, so you know what to expect and why.

  1. 01

    Assessing

    History and medication review

    Onset, one or both sides, colour, and a careful sweep of antipsychotics, antidepressants, antiemetics and other drugs known to raise prolactin.

  2. 02

    Assessing

    Menstrual and fertility history

    Amenorrhoea, oligomenorrhoea, subfertility and reduced libido point strongly to a hyperprolactinaemic cause.

  3. 03

    Assessing

    Breast and chest wall exam

    To confirm true galactorrhoea, exclude a breast lump, and check for chest wall triggers such as shingles, trauma or tight bras.

  4. 04

    Confirming

    Fasting morning prolactin

    Repeated if elevated, with a macroprolactin check to rule out biologically inactive large-molecular prolactin.

  5. 05

    Confirming

    TSH, pregnancy, U and Es, LFTs

    To catch hypothyroidism, pregnancy, chronic kidney disease and liver cirrhosis, all recognised causes.

  6. 06

    Specialist

    Pituitary MRI with gadolinium

    For persistently elevated prolactin without a medication or systemic cause, arranged through specialist endocrinology.

  7. 07

    Specialist

    Visual fields and DEXA

    Formal visual field testing for macroadenoma, and a DEXA scan when hyperprolactinaemia has been long-standing.

Typical timeline: most people have a working diagnosis within a few weeks.

Symptoms

What galactorrhoea actually looks like.

The classic mix of milky nipple discharge and hyperprolactinaemic features, alongside the clues that point elsewhere.

  • Bilateral milky discharge

    Classic picture, often spontaneous or easily expressible, and usually driven by raised prolactin.

  • Unilateral discharge

    Less typical of galactorrhoea, and more likely to reflect local breast pathology needing breast imaging.

  • Menstrual disturbance

    Amenorrhoea or oligomenorrhoea in women is a strong clue to hyperprolactinaemia.

  • Subfertility and low libido

    Prolactin excess suppresses the hypothalamic-pituitary-gonadal axis in both women and men.

  • Headache and visual changes

    Suggest mass effect from a macroprolactinoma pressing on the optic chiasm and need urgent imaging.

  • Reduced bone density

    Chronic hyperprolactinaemia lowers oestrogen or testosterone and increases osteoporosis risk.

  • Systemic clues

    Cold intolerance and fatigue for hypothyroidism, or features of chronic kidney or liver disease.

  • Red flag, bloody discharge

    Bloody or serous single-duct discharge points away from galactorrhoea and towards breast pathology.

Treatment

How galactorrhoea is treated in the UK.

Address the underlying cause first, use dopamine agonists for prolactinomas, and reserve surgery for a small subset of cases through specialist commissioned pituitary centres.

  • Medication rationalisation

    Reviewing antipsychotics, antidepressants and antiemetics with the prescribing team, and switching to prolactin-sparing options such as aripiprazole when appropriate.

  • Levothyroxine for hypothyroidism

    Treating primary hypothyroidism often normalises prolactin and settles galactorrhoea without further pituitary treatment.

  • Cabergoline

    First-line dopamine agonist for prolactinoma, taken twice weekly, usually well tolerated and highly effective at lowering prolactin.

  • Bromocriptine

    Older daily dopamine agonist, still used when cabergoline is not suitable, though more prone to nausea and postural symptoms.

  • Transsphenoidal surgery

    Reserved for dopamine-agonist resistant or intolerant prolactinomas, pituitary apoplexy and selected macroadenomas, at a specialist commissioned UK pituitary centre.

  • Pituitary radiotherapy

    A selective option for residual or resistant tumours after surgery, delivered by specialist neuro-oncology teams.

  • Bone protection

    DEXA-guided treatment with calcium, vitamin D and, where indicated, bisphosphonates to protect against osteoporosis.

  • Fertility and pregnancy planning

    Dopamine agonists often restore ovulation, and cabergoline is typically stopped in early pregnancy under specialist endocrine guidance.

What this guide is based on

The sources behind every claim on this page.

UK national guidance and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your GP or endocrinologist knows your history and can tell you which parts apply to you. If in doubt, get seen.

  • Endocrine Society. Diagnosis and treatment of hyperprolactinaemia clinical practice guideline.

  • Society for Endocrinology, UK. Guidance on pituitary tumours and prolactinoma management.

  • NICE Clinical Knowledge Summaries. Amenorrhoea and galactorrhoea.

  • Pituitary Foundation UK. Patient information on prolactinoma and hyperprolactinaemia.

Red flags

When galactorrhoea needs urgent attention.

Most cases are managed comfortably in primary and secondary care. These are the situations that need faster escalation.

  • Sudden severe headache

    With visual loss or ophthalmoplegia can indicate pituitary apoplexy, a neurosurgical emergency.

  • Visual field defect

    Bitemporal hemianopia suggests optic chiasm compression from a macroadenoma and needs urgent imaging.

  • Bloody or serous nipple discharge

    Points away from galactorrhoea and towards intraductal papilloma or breast cancer, and needs a breast clinic referral.

  • Persistent high prolactin off drugs

    When no medication or systemic cause is found, pituitary MRI and endocrinology review are essential.

  • New amenorrhoea with headache

    Combined menstrual disturbance and neurological features warrant prompt specialist assessment.

  • Suspected pregnancy

    Always excluded before any pituitary imaging or drug treatment for hyperprolactinaemia.

  • Rapid vision loss on dopamine agonist

    Rare tumour expansion or cerebrospinal fluid leak needs urgent specialist review.

  • Signs of hypopituitarism

    Fatigue, weight loss, low blood pressure and salt disturbance need urgent endocrine input.

  • Male galactorrhoea

    Uncommon and more likely to reflect a macroadenoma or significant hyperprolactinaemia, so always investigated fully.

Living with it

A treatable condition, with clear next steps.

Four things that make the biggest difference day to day, a rigorous medication review, tracking symptoms, protecting your bones and using trusted patient charities.

A quiet reminder

The right cause almost always has the right treatment.

A methodical approach to prolactin, medications and, where needed, pituitary imaging gets most people to a clear diagnosis and effective treatment.

  1. 01 Review

    Question every prescription

    Bring a full list of medications, including over-the-counter and recreational drugs, to every appointment. Many raise prolactin quietly.

  2. 02 Rhythm

    Track your cycle and symptoms

    A simple note of periods, headaches, visual symptoms and discharge helps your clinician see the pattern quickly.

  3. 03 Bones

    Protect your bone health

    Weight-bearing exercise, adequate calcium and vitamin D, and DEXA scanning where indicated, all matter for long-term bone strength.

  4. 04 Support

    Use trusted patient charities

    The Pituitary Foundation UK offers accurate information and peer support for people living with prolactinoma and hyperprolactinaemia.

Frequently asked

Everything we get asked about galactorrhoea.

Quick answers on prolactin, medications, prolactinoma treatment and pregnancy planning.

  • What is galactorrhoea?

    Galactorrhoea is milk-like nipple discharge that occurs outside of pregnancy and breastfeeding. It can affect one or both breasts and is usually driven by raised prolactin from medications, hypothyroidism, a prolactinoma or, less commonly, chronic kidney or liver disease.

  • Is galactorrhoea always a sign of a pituitary tumour?

    No. Many cases are caused by medications, thyroid problems or non-tumour hormonal changes, and some are idiopathic with a completely normal prolactin. A pituitary MRI is only arranged when prolactin is persistently elevated with no medication or systemic explanation.

  • Which medications can cause galactorrhoea?

    Antipsychotics such as risperidone, haloperidol, sulpiride and amisulpride are common culprits, along with some antidepressants, antiemetics like metoclopramide and domperidone, verapamil, methyldopa, cimetidine and opioids. Always review the full drug list before assuming another cause.

  • How is a prolactinoma treated in the UK?

    The first-line treatment is a dopamine agonist, most often cabergoline taken twice weekly. It lowers prolactin, shrinks the tumour and restores menstrual and fertility function in most people. Surgery at a specialist commissioned pituitary centre is reserved for resistant or intolerant cases and for pituitary apoplexy.

  • What is macroprolactin and why does it matter?

    Macroprolactin is a larger, biologically inactive form of prolactin that can falsely raise the measured level. If it is found, symptoms are usually mild, the pituitary is normal, and no dopamine agonist or imaging is needed. Ask about macroprolactin screening if your prolactin is high but you feel well.

  • Can I get pregnant if I have a prolactinoma?

    Yes. Treatment with cabergoline usually restores ovulation and fertility. Once pregnancy is confirmed, dopamine agonists are typically stopped and your endocrine and obstetric teams monitor you closely for symptoms of tumour growth throughout the pregnancy.

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