Hyperprolactinaemia (also written as hyperprolactinemia) is simply the medical term for having too much prolactin in your blood. It has a range of causes, and many cases can be treated. Here's what you need to know, from the early signs to what treatment looks like, and what it can mean for your fertility.

Prolactin is a hormone made by your pituitary gland, a pea-sized gland at the base of your brain. Its main job is to trigger milk production after childbirth, which is why it's sometimes called the "milk hormone". It's made in smaller amounts for men too.

Hyperprolactinaemia means your prolactin level is higher than it should be, outside of pregnancy or breastfeeding. Because prolactin can affect the hormones that control ovulation and sperm production, having too much of it can throw your reproductive hormones off balance. This is why it may be found during fertility tests, along with other causes such as irregular periods.

A mildly raised prolactin result does not always mean that treatment is needed. Your doctor will look at how high the level is, whether you have symptoms, what may be causing it, and whether you're trying to conceive. In some cases, a repeat blood test or further checks may be all that's needed.

Symptoms of hyperprolactinaemia

The signs of hyperprolactinaemia depend on your sex, how high your prolactin level is, and what is causing it. Symptoms can also build slowly, so it is easy to put them down to stress or a busy few months before seeing a link.

Hyperprolactinaemia symptoms in women

Symptoms of hyperprolactinaemia in women often show up first as changes to your menstrual cycle. Common signs include:

• Irregular periods or periods stopping altogether

• Breast milk leaking when you're not pregnant or breastfeeding (galactorrhoea)

• Reduced interest in sex

• Difficulty conceiving

These symptoms happen because excess prolactin can affect the hormones that control ovulation and the menstrual cycle. Irregular periods are also worth flagging with your GP in their own right, since they can point to several different causes.

Hyperprolactinaemia symptoms in men

In men, high prolactin can lower testosterone, which can lead to:

• Reduced interest in sex or erectile difficulties

• A lower sperm count and reduced fertility

• Occasionally, breast enlargement

Because these symptoms can have many causes, hyperprolactinaemia in men may only be picked up during fertility tests.

When symptoms are more serious

Very rarely, hyperprolactinaemia is caused by a larger pituitary growth pressing on nearby parts of the brain. If this happens, you might notice headaches or changes to your vision.

These symptoms need prompt medical attention, so see your GP if they occur.

What causes hyperprolactinaemia?

There isn't just one cause of hyperprolactinaemia. Some causes are normal changes in the body, while others need medical care. The main causes include:

• Physiological causes. Pregnancy, breastfeeding, nipple stimulation, stress and exercise can all raise prolactin for a short time.

• Medication. Some medicines, in particular certain antipsychotics and anti-nausea drugs, can raise prolactin levels.

• An underactive thyroid. Hypothyroidism can push prolactin up. It can be checked with a blood test and is treated with thyroid hormone tablets.

• A prolactinoma. This is a benign, non-cancerous growth on the pituitary gland that makes prolactin. It is the most common type of hormone-making pituitary tumour. Most are small, known as microprolactinomas, and many grow very slowly or not at all.

If your doctor thinks a temporary cause or a medicine may be behind the raised result, they may repeat the blood test and check your thyroid. What happens next will depend on the level, your symptoms and the likely cause.

Mild hyperprolactinaemia: does it need treatment?

Not always. A mildly raised prolactin result does not by itself mean that you have a serious illness or that you need medicine.

Your doctor will look at the full picture. This may include how high your prolactin is, whether you have symptoms, whether a medicine or another health problem could be causing it, and whether you are trying to conceive.

Some people with a mild rise may simply need another blood test or follow-up. Others may need treatment if the high prolactin is linked to symptoms, a prolactinoma, problems with periods or ovulation, or fertility problems.

So, if you've had a raised result, it is better not to assume that it is either harmless or serious based on the number alone. Your doctor can help work out what it means in your case.

Hyperprolactinaemia and fertility

Hyperprolactinaemia and infertility are closely linked, which is often how the condition first comes to light. High prolactin can stop or reduce ovulation in women and can affect sperm production in men, both of which can make conceiving harder.

The encouraging news is that fertility problems caused by high prolactin can often improve when the cause is treated. In women, periods and ovulation may return as prolactin levels come down. In men, sperm production may also improve, although the time this takes can vary.

If you've been trying to conceive for a year without success, speak to your GP. If you're aged 36 or over, or you already know that you may have a fertility problem, it is a good idea to seek advice sooner. Your GP can check for common causes of fertility problems, including hormone problems, and refer you on if needed.¹

Hyperprolactinaemia and pregnancy

If you're diagnosed with hyperprolactinaemia or a prolactinoma and later become pregnant, speak to your doctor or specialist team before changing any medicine.

Many women with a small prolactinoma are advised to stop dopamine-agonist treatment once pregnancy is confirmed. However, this is not right for everyone, so your specialist team will advise what is best for you.²

For most women with a small prolactinoma, the risk of the tumour growing during pregnancy is low. If you develop new or worse headaches or any changes to your vision while pregnant, contact your doctor promptly so they can check you.

How is hyperprolactinaemia diagnosed?

Diagnosis usually starts with a blood test to measure your prolactin level. Because prolactin can rise for a short time due to things such as stress or exercise, your doctor may repeat the test to make sure the result is still high.³

They may also check your thyroid function, since an underactive thyroid can raise prolactin.

In some cases, the lab may check for macroprolactin. This is a form of prolactin that can make the blood test look high but has little effect in the body. Finding it can help doctors avoid tests or treatment that you may not need.³

If the prolactin level is high enough to suggest a pituitary cause, or there is no clear reason for the result, you may be referred for an MRI scan of your pituitary gland. This can help find or rule out a prolactinoma.³

If you have vision changes, you may also need a check of your eyesight or visual field.

Hyperprolactinaemia treatment

The right treatment depends on the cause.

If a medicine is responsible, your doctor may review your prescription and decide whether it should be changed. Do not stop a prescribed medicine on your own, as some medicines need to be reduced slowly or replaced with another treatment.

If high prolactin is linked to an underactive thyroid, treating the thyroid problem with thyroid hormone can bring the prolactin level down.

For a prolactinoma, treatment is usually with medicines called dopamine agonists. These reduce the amount of prolactin made by the tumour and can also shrink it. Cabergoline is a common choice, while bromocriptine may also be used in some cases.

For people with ovulation problems caused by high prolactin, current NICE guidance recommends cabergoline. NICE found that cabergoline can help restore periods and improve the chance of pregnancy, and noted that it has fewer side effects and needs to be taken less often than bromocriptine.⁴

Prolactin levels can fall quite quickly after treatment starts, but the time it takes for symptoms, periods or fertility to improve can vary from person to person.

Surgery is only needed in some people, such as when medicine does not work well enough, cannot be tolerated, or there is another reason why surgery is needed.

Treatment may be long-term. In some people, a specialist may later suggest stopping the medicine to see if the prolactin level stays normal. This is decided on an individual basis, based on things such as the prolactin level, symptoms and the size and behaviour of any prolactinoma.

Trying to conceive while managing hyperprolactinaemia

Getting a diagnosis like this while you're trying for a baby can feel like one more thing standing in your way. But when high prolactin is the cause of a fertility problem, treating it can often help restore normal ovulation and improve the chance of pregnancy.

While you and your doctor work through diagnosis and treatment, it can help to keep trying at home in a way that feels less pressured. This is where the twoplus Applicator Extra may fit into your routine. It's an at-home insemination kit designed to deposit sperm close to the cervix, using the same basic approach as intracervical insemination (ICI).

The Applicator can't treat hyperprolactinaemia itself. That needs the medical treatment your doctor prescribes. If you are thinking about using an at-home insemination product, talk to your GP or fertility team about whether it is suitable for you, especially if you have a known fertility problem.

If you suspect a hormone imbalance or have been struggling to conceive, talk to your GP first so any cause can be found and treated.

FAQs

Can hyperprolactinaemia go away on its own?

Sometimes. If it is caused by something temporary, such as stress, certain medicines or another short-term change, prolactin levels may return to normal when the cause is dealt with. If it is caused by a prolactinoma, you may need medicine or other treatment. Some people can later stop treatment under medical supervision.

Can I get pregnant with hyperprolactinaemia?

Yes. Many people with hyperprolactinaemia go on to conceive, especially when the cause is found and treated. The outlook depends on what is causing the high prolactin and whether it affects ovulation or sperm production.

If you're trying for a baby, speak to your GP or fertility specialist so you can get the right tests and treatment.

What counts as a high prolactin level?

Normal prolactin levels vary between labs, so there is no single number that applies to everyone. Your doctor will compare your result with the range used by the lab that tested your blood and look at it alongside your symptoms and other test results.

Is mild hyperprolactinaemia serious?

A mild rise does not always mean there is a serious problem, but it should still be looked at in context. Your doctor may repeat the test, look for a cause or simply keep an eye on the level. Treatment may be needed if the raised prolactin is causing symptoms, affecting fertility or linked to a condition such as a prolactinoma.

How long does treatment take to restore fertility?

This varies. Prolactin can often fall within weeks of starting treatment, but it can take longer for periods, ovulation or sperm production to improve. Your doctor can give you a better idea based on the cause of your high prolactin and your test results.

Sources

1. NHS – Infertility: https://www.nhs.uk/conditions/infertility/

2. Pituitary Foundation – Prolactinoma: https://www.pituitary.org.uk/information/prolactinoma/

3. Royal United Hospitals Bath NHS Foundation Trust – Hyperprolactinaemia: A Guide for GPs: https://www.ruh.nhs.uk/pathology/documents/clinical_guidelines/PATH_026_Hyperprolactinaemia_A_Guide_for_GPs.pdf

4. NICE – Fertility problems: assessment and treatment (NG257), 2026: https://www.nice.org.uk/guidance/ng257