Hormones

Prolactin — The Quiet Disruptor of Fertility and Libido

Most people associate prolactin with breastfeeding, and fair enough — that's its headline act. But this pituitary hormone also plays a behind-the-scenes role in fertility, menstrual regulation, fat metabolism, and sexual satisfaction in both women and men. When prolactin is elevated outside of pregnancy and breastfeeding, it can quietly disrupt the whole hormonal orchestra.

Why Test Prolactin?

Testing prolactin makes sense when there's unexplained breast milk production, abnormal nipple discharge, periods that have gone AWOL, fertility struggles, or — in men — decreased libido or erectile dysfunction. It's also used for monitoring prolactin-secreting tumours (prolactinomas) and as follow-up when testosterone is low.

What Do High Prolactin Levels Mean?

High prolactin is perfectly normal during pregnancy and breastfeeding. Otherwise, elevated levels may link to hypothyroidism, intense exercise, birth control pills, pituitary tumours (prolactinomas), PCOS, eating disorders, stress, and various medications including estrogen, antidepressants, and antipsychotics.

What Do Low Prolactin Levels Mean?

Prolactin is normally low in men and non-pregnant women. If it dips below the reference range, it's not usually a problem — but mention it to your doctor.

Symptoms to Watch For

  • Unexplained breast milk production (galactorrhoea)
  • Abnormal nipple discharge
  • Absent or irregular periods
  • Infertility
  • Decreased libido or erectile dysfunction
  • Headaches or vision changes (if prolactinoma)

Who Should Get Tested?

  • Women with unexplained milk production or nipple discharge
  • Those with absent or irregular periods
  • Men with low testosterone or erectile dysfunction
  • Patients being monitored for prolactinomas
  • Anyone going through a fertility evaluation

How to Prepare for Your Test

Avoid alcohol the day before. Take the test before 10 am. Arrive early and sit quietly for 15 minutes — stress can temporarily spike prolactin. Bring valid ID. If you take a supplement containing biotin (often sold for hair and nails), pause it for two days before the test, as high doses can distort the result.

Order Your Blood Test

Test your Prolactin levels with an accredited Swedish laboratory. Results within days, reviewed by Wellth.

Prolactin →

Frequently Asked Questions

Can stress affect prolactin levels?
Yes, especially in men. Both physical and emotional stress can bump up prolactin temporarily. That 15-minute rest before the blood draw really matters here.
What is a prolactinoma?
A prolactinoma is a benign pituitary tumour that overproduces prolactin. It can cause milk production, cycle changes, or vision issues. The good news: it's usually very treatable with medication.
Can medications affect prolactin?
Many can — including antipsychotics, antidepressants, estrogen, and some blood pressure drugs. Always mention your medications when reviewing results.
NW

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Wellth Team

Wellth

Our content is written and reviewed by Wellth, and fact-checked against peer-reviewed research and current Swedish clinical guidelines.

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Medical Disclaimer

The information on this page is provided for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment. Wellth provides health information and testing services but is not a substitute for clinical care. Always consult a qualified healthcare provider if you have questions about a medical condition. If you are experiencing severe or urgent symptoms, contact your doctor or call 1177 Vårdguiden. Blood test results should be interpreted by a qualified healthcare professional in the context of your complete medical history.