Understanding Prolactin: Normal vs Optimal Ranges

?What is Prolactin?

Prolactin is a hormone produced by the pituitary gland that stimulates breast milk production. Outside of pregnancy and breastfeeding, elevated prolactin (hyperprolactinaemia) is abnormal and can suppress reproductive function in both men and women.

!Why It Matters

Elevated prolactin suppresses FSH and LH, causing irregular or absent periods in women, infertility, low testosterone in men, and reduced libido in both sexes. The most common cause is a prolactinoma — a benign pituitary tumour. Other causes include antipsychotic medications, hypothyroidism, and chronic stress.

Reference Ranges

Lab normal ranges may vary between laboratories. Optimal and longevity targets are based on research literature and should be interpreted with your physician.

Symptoms of Imbalance

• Galactorrhoea (inappropriate breast milk production)
• Irregular or absent periods
• Infertility
• Low libido in men and women
• Headache and visual changes if prolactinoma is large

How to Improve Your Levels

• 1Cabergoline or bromocriptine effectively lower prolactin in prolactinomas
• 2Treat underlying hypothyroidism or medication causes

When to Test

Test in the morning (prolactin is diurnal), fasting, and at rest (stress and recent sexual activity can transiently elevate prolactin). Test if: infertility, irregular periods, low testosterone, or galactorrhoea.

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