What is this test?
Macroprolactin is a large form of prolactin associated with antibodies and usually with less biological activity. The test helps clarify elevated total prolactin.
Why might it be ordered?
- With repeated increased prolactin, especially when typical symptoms are absent.
- To assess how much of the measured prolactin is more biologically active.
What sample is needed?
A healthcare professional collects a venous blood sample. Depending on the method, the laboratory uses serum or plasma.
How should you prepare?
Follow the same conditions as for prolactin: instructions for time, rest and avoiding heavy exercise immediately before the sample. Tell the laboratory about all medicines, hormone treatments, vitamins and supplements you take. Do not stop or change treatment unless your clinician tells you to. Follow any instructions about fasting and the time of collection.
How should you understand the result?
The result is interpreted with total prolactin and the percentage recovered after laboratory treatment, according to the method used. Your result is interpreted using the reference interval on the laboratory report and in the context of your symptoms, medical history and other test findings.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.