Prolactin
Disclaimer: Information on this page is for educational purposes. Consult a physician to interpret your test results. Health Vault helps track biomarker trends but does not replace medical advice.
What This Test Measures
Prolactin stimulates lactation. Elevation suppresses GnRH causing amenorrhea and galactorrhea.
Macroprolactin is inactive and may cause false elevation.
Stress raises prolactin — repeat testing recommended.
Normal Ranges
| Group | Reference Range |
|---|---|
| Men | 4–15 ng/mL (86–324 mIU/L) |
| Women | 4–15 ng/mL |
| Children | Age dependent |
Reference ranges may vary by laboratory and assay method.
Causes of High Levels
- Prolactinoma
- Hypothyroidism
- Antipsychotics
- Pregnancy, lactation
Causes of Low Levels
- Rarely clinically significant
Test Preparation
- Morning draw
- Avoid breast exam before test
- Report antipsychotics
Related Biomarkers
| Biomarker | Relationship |
|---|---|
| Thyroid Stimulating Hormone (TSH) | Secondary hyperprolactinemia |
| Testosterone | Suppressed axis |
| Estradiol | Hypogonadism |
FAQ
How often should I take this test?
With amenorrhea/galactorrhea — initial + repeat.
What should I do if my result is abnormal?
Persistent elevation — pituitary MRI; rule out macroprolactin and hypothyroidism.
Last updated: June 2026