Pathology Handbook


Clinical Indications

Prolactin should be measured as part of investigations into loss of libido, infertility, menstrual disturbances and gynaecomastia. Prolactin-secreting tumours can present with visual disturbance, headache etc.
The use of prolactin levels in providing supportive evidence for a genuinely epilepetic seizure is severely limited by the need for a sample within 30 minutes of the fit.

Elevated prolactin levels may occur due to (the 5 p's):

  • Physiological - stress, exercise, lactation, pregnancy

  • Pharmacological - drugs, especially neuroleptics, antiemetics, SSRI's

  • Pituitary - prolactinoma or other tumour causing stalk compression

  • Non-Pituitary - PCOS, hypothyroidism, renal failure

  • Problems - Macroprolactin (non-pathological increase in apparent prolactin)

Request Form

Request on ICE


On request.

Turnaround Time

Same day


Serum in yellow top (SST) tube


2 ml


Vacutainer gold top

Causes for Rejection

Unlabelled sample

Reference Range

Males: Less than 325 U/L

Females: Less than 500 U/L

Levels of up to twice the reference range may be the result of stress.

The laboratory will automatically investigate samples with raised prolactin for macroprolactin.