What is the Prolactin test?

The Prolactin blood test measures prolactin, a hormone produced by the pituitary gland that plays a key role in breast development and milk production. Prolactin also influences reproductive hormones and menstrual cycle regulation.

Outside pregnancy and breastfeeding, prolactin levels are usually low. Elevated or reduced levels can disrupt ovulation, testosterone production, and overall hormonal balance.

This test is commonly used as part of fertility assessment, menstrual irregularity investigation, and pituitary gland evaluation.

Why do I need a test for Prolactin?

Abnormal prolactin levels can interfere with reproductive hormones and cause a wide range of symptoms in both women and men. Testing helps identify whether prolactin imbalance is contributing to fertility issues or hormonal symptoms.

It is particularly useful when investigating irregular periods, infertility, sexual dysfunction, or symptoms suggesting pituitary involvement.

You may benefit from this test if you experience:

• Irregular or absent menstrual cycles

• Difficulty conceiving

• Milk discharge from breasts (not pregnant or breastfeeding)

• Low libido or sexual dysfunction

• Erectile dysfunction in men

• Headaches or visual disturbances

• Suspected pituitary disorders

• Hormonal imbalance symptoms

Benefits of the Prolactin test

1. Assesses pituitary gland function
   Helps evaluate hormone production from the pituitary.

2. Supports fertility investigation
   High prolactin can suppress ovulation and sperm production.

3. Investigates menstrual irregularities
   Identifies hormonal causes of cycle disruption.

4. Evaluates unexplained breast discharge
   Helps assess galactorrhoea.

5. Relevant for male hormonal health
   Elevated prolactin can lower testosterone levels.

6. Supports diagnosis of pituitary disorders
   Useful in suspected prolactin-secreting adenomas.

7. Guides further endocrine testing
   Abnormal results may prompt additional hormone assessment.

8. Non-invasive hormone assessment
   Requires only a blood sample.

Step-by-step – how we offer Prolactin testing

Clinic-based testing (UK-wide)

• Choose your nearest UK clinic

• Attend your appointment

• Blood sample collected by a qualified clinician or phlebotomist

• Sample is sent to the laboratory for analysis

At-home or hotel testing (+£60)

• A qualified phlebotomist visits your home or hotel

• Blood sample collected in a comfortable, familiar setting

• No clinic visit or travel required

Both services are available UK-wide.

Your Prolactin results explained

Low prolactin levels

Low prolactin levels are uncommon and usually not clinically significant. In rare cases, they may indicate reduced pituitary function.

Low levels are generally not associated with symptoms unless part of broader pituitary dysfunction.

UK reference interpretation:

• Low: Below laboratory reference range

Normal prolactin levels

Normal prolactin levels indicate balanced pituitary hormone production. This supports normal reproductive hormone regulation.

Results should be interpreted alongside symptoms and other hormone levels.

UK reference interpretation:

• Normal: Within laboratory reference range

High prolactin levels (hyperprolactinaemia)

Elevated prolactin levels can suppress ovulation, reduce testosterone, and cause fertility or sexual dysfunction. Causes include stress, certain medications, thyroid dysfunction, or pituitary adenomas.

Persistently high levels often require further endocrine evaluation.

UK reference interpretation:

• High: Above laboratory reference range