A patient seated in the chair before a blood draw
In person

Prolactin

Your level of prolactin, a pituitary hormone, from one blood draw.

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  • 2,000+ lab locations. Find one near you
  • Nothing due at the lab. FSA / HSA accepted
  • Ordered by a licensed clinician

At a glance

Collection
Blood draw
A standard blood draw at the lab.
Preparation
Fasting preferred
Fast 8 to 12 hours. Water is fine.
Results
1 to 3 days
Typical turnaround after your visit.
Where
2,000+ lab locations
Nationwide, with nothing due at the lab.

About this test

Made by the pituitary gland, prolactin rises in pregnancy and breastfeeding to support milk production. A high level at other times can affect periods, sex drive, and fertility. Stress, exercise, and sleep can raise it briefly, and fasting beforehand is preferred.

For adults 18 and older. Test availability varies by lab location.

Who should take this test?

This test is often used by adults with missed or irregular periods, unexpected milk from the breasts, or changes in sex drive or erections. Commonly related symptoms include:

Reproductive

  • Missed periods
  • Irregular periods
  • Trouble conceiving

Body

  • Milky nipple discharge

Sexual

  • Low sex drive
  • Erectile changes

Ask about this test

Not sure this is the right test?

AI-generated. For information only, not medical advice. Call 911 for an emergency.

What does this test measure?

Your result shows how much prolactin is in your blood, which a healthcare provider can read with your symptoms, your medicines, and other hormones such as TSH.

Prolactin
Prolactin is a hormone made by the pituitary gland that supports breast milk production. Levels rise sharply in pregnancy and breastfeeding. Stress, exercise, sleep, and some medicines can raise it briefly, so a higher result is often repeated before it is read.
Why it’s measured: A pituitary hormone that, when high, can affect other reproductive hormones.

How it works

  1. Step 1

    Order online

    Check out here. A licensed clinician in your state reviews your order and sends it to the lab.

  2. Step 2

    Visit a lab

    Bring a photo ID to any of 2,000+ lab locations. Fast 8 to 12 hours. Water is fine. Nothing is due at the lab.

  3. Step 3

    Get your results

    Results post to your account, usually in 1 to 3 days, each number next to the lab’s reference range.

Find a lab near you

Choose from 2,000+ lab locations nationwide. Your order works at any of them.

What your results tell you

Prolactin is reported in nanograms per milliliter (ng/mL) and compared with the lab’s reference range. A high result is often repeated.

  • Your number next to the lab’s reference range
  • Explained in plain language
  • A licensed clinician reviews your order and, if appropriate, orders the test.
  • A lab report you can download and share

A healthcare provider reads prolactin with your symptoms, medicines, and other results, and decides whether a repeat or added test is needed.

Clinical-grade testing, from the comfort of home.

From the lab to your report, every step of our process meets the gold standard in medical testing.

  • CLIA-certified labs

    Every lab we partner with is certified under the Clinical Laboratory Improvement Amendments, meeting both state and federal standards with regular independent inspections.

  • We protect your health data

    We protect your health data with encryption and do not sell it. Some results must be reported to public health authorities by law. See our Privacy Notice.

  • Rigorous quality assurance

    All partner labs run regular internal quality checks, participate in proficiency testing, and comply with federal and state lab regulations.

  • Clinician-reviewed reports

    Results are reviewed by an independent, licensed clinician.

Questions

Common questions.

Anything else, our care team answers by phone, text, or email.

Stress, exercise, and sleep can each raise prolactin briefly, so one high result may not reflect your usual level. The lab also prefers an overnight fast before this test.

For these reasons, a healthcare provider often repeats a high result before drawing any conclusion.

Yes. The lab notes that a number of medicines, including many antidepressants, can raise prolactin. Tell your healthcare provider about all the medicines you take. Don’t stop or change any medicine or supplement without talking with your healthcare provider.

Prolactin is naturally high in pregnancy and breastfeeding. Outside those times, a level that stays high can have several causes, including an underactive thyroid, kidney problems, some medicines, or changes in the pituitary gland.

A healthcare provider works out the cause, often with repeat testing and other tests.

One prolactin result cannot say why a level is high, and a single high result may reflect a brief rise rather than an ongoing one. This test also does not check your thyroid or other pituitary hormones, which a healthcare provider may add.

Lab tests are informational and don’t diagnose conditions on their own. Available to adults 18 and older; test availability varies by lab location. A licensed clinician reviews your order and, if appropriate, orders the test. All testing is performed at CLIA-certified laboratories. Not for emergencies: if you think you may be having a medical emergency, call 911.