Prolactin Serum Test

Quick Facts

• Sample: Blood draw from vein
• Fasting: 8-hour fasting may be required
• Turn-around: 1-2 days. May take longer based on weather, holiday, or lab delays.

Benefits

• Detect pituitary tumors early - screen for prolactinomas with 95% accuracy 
• Evaluate fertility issues - identify hormonal causes of infertility problems
• Monitor treatment response - track medication effectiveness for pituitary disorders 
• Convenient at-home testing - no doctor's visit required for ordering 
• Confidential health screening - private assessment of reproductive hormone levels 
• Cost-effective diagnosis - reduce need for expensive imaging procedures

Who Is This Test For?

• Women experiencing irregular periods or unexplained infertility 
• Individuals with unusual breast discharge or milk production 
• Men with low sex drive or erectile dysfunction 
• Anyone with suspected pituitary gland disorders 
• People monitoring prolactin-affecting medication effects 
• Those with headaches and vision problems combined with hormonal symptoms

How It Works – Just 3 Steps

• Order online - purchase your test kit without a prescription
• Visit lab - get blood drawn at any convenient location
• Get results - receive secure results within 1-2 days

FAQ

What does this test measure? This test measures prolactin hormone levels in your blood to detect pituitary disorders and evaluate reproductive health.

Do I need to prepare for this test? Some labs require 8-hour fasting. Schedule morning collection 3-4 hours after waking for most accurate results.

What are normal prolactin levels? Normal ranges are less than 20 ng/mL for men and less than 25 ng/mL for non-pregnant women.

Can medications affect my results? Yes, certain medications can raise prolactin levels. Discuss your medications with your healthcare provider before testing.

How accurate is this test? Research shows this test achieves 89-95% sensitivity and 82-95% specificity for detecting prolactinomas (Nature 2021).

When will I get my results? Most results are available within 1-2 business days.

More Details

What is the purpose of this test?

The prolactin serum test measures prolactin hormone levels to diagnose pituitary tumors called prolactinomas, evaluate fertility issues, and assess causes of irregular menstruation or unexplained milk production. Prolactin is produced by the pituitary gland and primarily regulates breast development and milk production (Mayo Clinic 2023).

This test uses electrochemiluminescence immunoassay methodology to provide highly accurate results. Prolactinomas represent 45% of all pituitary adenomas, making this the most common type of pituitary tumor with a worldwide prevalence of 6-10 per 100,000 persons (Medscape 2022).

Who would benefit from this test?

Women with irregular periods, fertility problems, or unexplained breast discharge benefit most from this test. Men experiencing erectile dysfunction or decreased libido should also consider testing. The test is particularly valuable for reproductive-age individuals, as prolactinomas affect women 10-14 times more frequently than men in this age group (Endocrine Society 2020).

Anyone with suspected pituitary disorders, those monitoring medication effects on prolactin levels, or individuals experiencing symptoms like headaches combined with vision problems should consider this test. Healthcare-conscious consumers who prefer direct access to diagnostic information will find this test especially valuable.

When should I order a Prolactin Serum Test?

Order this test when experiencing fertility issues, irregular menstrual cycles, unexplained breast milk production, decreased sex drive, or symptoms suggesting pituitary disorders. Schedule testing if you have persistent headaches combined with vision problems, as these may indicate a pituitary tumor (UCSF Health 2025).

Consider testing before starting medications known to affect prolactin levels or when monitoring treatment effectiveness for diagnosed prolactinomas. Women experiencing unexplained infertility should include prolactin testing as part of comprehensive hormone evaluation.

How do I interpret the results?

Prolactin Level: Men <20 ng/mL; Women <25 ng/mL

• What it means: Normal range
• Typical action: No action needed

30–85 ng/mL

• What it means: Mild elevation
• Typical action: Repeat testing, evaluate symptoms

85–213 ng/mL

• What it means: Moderate elevation
• Typical action: Further evaluation, possible imaging

>213 ng/mL

• What it means: Severe elevation
• Typical action: Urgent endocrinology referral

Levels above 250 ng/mL strongly suggest macroadenomas, while levels exceeding 500 ng/mL typically indicate macroprolactinoma requiring immediate treatment.

Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.

Pre-test preparation

Some labs require 8-hour fasting for most accurate results. Schedule your blood draw in the morning, 3-4 hours after waking, when prolactin levels are most stable. Avoid strenuous exercise and excessive stress before testing, as these can artificially elevate prolactin levels (Testing.com 2024).

Avoid biotin supplements for 12 hours before testing. Discuss any medications with your healthcare provider, as certain drugs can affect prolactin levels. Women should consider their menstrual cycle timing, though this test can be performed at any time.

How often should I get tested?

• Initial screening: Once, then as symptoms warrant
• Elevated results: Repeat in 4 weeks to confirm
• Monitoring medication effects: Every 3–6 months
• Active prolactinoma treatment: Every 3–4 months initially
• Fertility evaluation: As part of initial hormone panel

Why early detection matters

Early detection of prolactinomas prevents complications like vision loss, headaches, and reproductive dysfunction. Untreated prolactinomas can grow and damage surrounding brain tissue, potentially causing permanent vision problems. Research shows that proper prolactin testing can save healthcare systems up to £13,000 per 46 patients by reducing unnecessary MRI scans (Cleveland Clinic 2023).

Early identification allows for effective medical treatment with dopamine agonist medications, often avoiding the need for surgery. Prompt diagnosis and treatment help restore normal reproductive function and prevent long-term complications.

Related tests you may consider

TSH (Thyroid Stimulating Hormone) - Essential complementary test as hypothyroidism can cause elevated prolactin levels, and thyroid disorders frequently coexist with pituitary dysfunction.

LH/FSH- Valuable for comprehensive hormone assessment, as prolactin elevation can suppress LH and FSH, affecting fertility and reproductive function.

Hormone #2 Essential Blood Test Panel, Women – Evaluates key female hormones including Estradiol, Progesterone, Cortisol, FSH, LH, DHEA-S, TSH, T3, T4, IGF-1, and Total and Free Testosterone to help assess menstrual irregularities, fertility concerns, and symptoms of hormonal imbalance.