Prolactin
A pituitary hormone that, when elevated, can suppress the entire male reproductive axis.
What it is
Prolactin is produced by lactotrope cells in the anterior pituitary. In men it has subtle physiological roles, but it matters clinically because hyperprolactinaemia — most often from a benign pituitary adenoma (prolactinoma) or certain medications — directly suppresses GnRH and therefore LH, FSH and testosterone.
Why it matters
Hyperprolactinaemia is one of the few reversible, medication-treatable causes of low testosterone and low libido. Missing it means treating the symptom (low T) without addressing the cause.
Adult male reference range
Adult male reference range is roughly 4–15.2 ng/mL (≈ 86–324 mIU/L).
Role on the panel
On the Hormone Panel 01, prolactin is the screening marker for an upstream pituitary cause of low testosterone. A clearly elevated value warrants imaging and an endocrinology referral.
When it reads low
Low prolactin is rarely clinically meaningful in men.
When it reads high
Elevated prolactin in a man with low T, low libido or erectile dysfunction is a flag for prolactinoma, dopamine-blocking medication (some antipsychotics, SSRIs, opioids), severe stress, or rarely hypothyroidism.
Common questions about this marker.
Order the Hormone Panel 01.
All six markers, one finger-prick, ISO-certified German lab. Physician review and a plain-language report in 3–5 working days.