What this marker measures
Prolactin rises with physical or emotional stress, exercise, and sleep, so a single elevated result should be confirmed with a repeat test under controlled conditions. It is also naturally very high throughout pregnancy and breastfeeding.
High or low: what it can mean
High Prolactin
Elevated prolactin (hyperprolactinemia) can disrupt menstrual cycles in females and cause low testosterone and sexual dysfunction in males. Common causes include a benign pituitary tumour (prolactinoma), certain medications (antipsychotics, metoclopramide), stress, and hypothyroidism.
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Low Prolactin
Low prolactin is not generally clinically significant outside of an established diagnosis of pituitary hormone deficiency.
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Lifestyle considerations
- •Blood should be drawn fasting and after 30 minutes of rest for the most accurate prolactin result
Frequently asked questions
What is Prolactin?
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Prolactin is a hormone produced by the pituitary gland that stimulates breast milk production after childbirth. In non-pregnant individuals, it plays roles in immune function and reproductive regulation.
What does Prolactin measure?
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Prolactin rises with physical or emotional stress, exercise, and sleep, so a single elevated result should be confirmed with a repeat test under controlled conditions. It is also naturally very high throughout pregnancy and breastfeeding.
What does high Prolactin mean?
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Elevated prolactin (hyperprolactinemia) can disrupt menstrual cycles in females and cause low testosterone and sexual dysfunction in males. Common causes include a benign pituitary tumour (prolactinoma), certain medications (antipsychotics, metoclopramide), stress, and hypothyroidism.
What does low Prolactin mean?
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Low prolactin is not generally clinically significant outside of an established diagnosis of pituitary hormone deficiency.
What supports healthy Prolactin levels?
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Blood should be drawn fasting and after 30 minutes of rest for the most accurate prolactin result
Related biomarkers
Editorial note
LabTestly explains lab markers using plain-English educational content. Reference ranges may vary by laboratory and should be interpreted with a clinician.
Educational content · Editorially reviewed for clarity · Last updated
Common sources used for lab-test education
Not medical advice
This page is for general understanding only and does not replace medical advice from your clinician. Reference ranges can vary by laboratory, age, sex, pregnancy status, medications, and clinical context.