Prolactin Blood Test (PRL)

Prolactin (PRL) is a hormone produced by the pituitary gland, best known for its role in breast milk production after childbirth. However, it also plays a part in regulating the menstrual cycle, ovulation, and testosterone production. This test measures the level of prolactin in your blood to help identify whether an elevated level (hyperprolactinaemia) might be affecting your fertility or reproductive health.

This test is suitable for anyone experiencing unexplained infertility, irregular or absent periods, nipple discharge, erectile dysfunction, low libido, or symptoms such as headaches and visual disturbances that can accompany a prolactinoma (a benign pituitary tumour). It is also used to monitor response to treatment for high prolactin levels.

The test is performed using a simple blood sample, analysed with an immunoassay technique. For accurate results, the sample is ideally taken in the morning after a few hours of fasting and avoiding strenuous exercise or nipple stimulation beforehand, as these can temporarily raise prolactin levels.

Biomarkers included

Prolactin
- Prolactin (PRL)

Why it matters
Prolactin imbalances are a treatable cause of infertility and menstrual disturbance. Identifying high prolactin early allows your doctor to investigate the underlying cause, such as a pituitary adenoma, thyroid dysfunction, or medication side effects, and to offer appropriate treatment. Normalising prolactin levels can restore ovulation, improve fertility, and resolve related symptoms, making this a valuable first-line test in fertility investigations.

Prolactin
- Prolactin (PRL)

No special preparation required.

For blood tests, we recommend drinking plenty of water beforehand to ensure smooth sample collection. If you are taking any regular medication, continue to do so unless advised otherwise by your doctor.