What is Prolactin?
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.
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.
Why might Prolactin be high?
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.
This information is educational. A single out-of-range result is rarely the whole picture — a healthcare professional can interpret your numbers alongside your overall health and history.
Context questions that matter
- →Was this result slightly or clearly outside the reference range?
- →Were related markers also high or low?
- →Is this new compared with previous tests?
- →Could recent illness, exercise, fasting, alcohol, supplements, or medication affect it?
- →Do you have symptoms that should be discussed with a clinician?
Lifestyle considerations
- •Blood should be drawn fasting and after 30 minutes of rest for the most accurate prolactin result
Questions to ask your doctor
- →Could time of day, cycle phase, stress, sleep, medication or supplements affect this result?
- →How does this compare with related hormones such as LH, FSH, testosterone, estradiol, prolactin, cortisol or DHEA-S?
- →Is this a one-time result, or part of a pattern that needs repeat testing?
Don't guess from one flagged result.
Start with the most relevant panel and see how your markers fit together in plain English.
Frequently asked questions
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 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.
Does timing matter for hormone tests?
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Often yes. Time of day, menstrual cycle phase, sleep, acute stress, medications and supplements can all affect hormone results. Morning samples and same-time-of-day repeat testing are typically preferred for hormones with a daily rhythm.
Should hormone results be compared with related hormones?
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Yes — hormones are usually interpreted as patterns. TSH is read with Free T4 and Free T3; testosterone is read with LH, FSH and SHBG; cortisol is read with ACTH and the time of day. Single values out of context can be misleading.
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