Prolactin, Active & macroprolactin

You should get an active prolactin and macroprolactin test if your prolactin is high but you have few or no symptoms, or if symptoms don't match your prolactin level. It is also recommended before an MRI or starting treatment for hyperprolactinemia, and when high prolactin persists despite treatment, to rule out macroprolactinemia.

Fasting is usually not required for an active prolactin and macroprolactin test, but avoid a heavy meal beforehand. Give your sample 3–4 hours after waking, and rest for 15–30 minutes before collection. Avoid stress, strenuous exercise, sexual activity, and nipple stimulation for 24 hours, and inform your doctor about any medicines.

Fasting is usually not required for an active prolactin and macroprolactin test, though you should avoid a heavy or high-protein meal beforehand. More importantly, give your sample 3–4 hours after waking, rest for 15–30 minutes before collection, and avoid stress, exercise, and sexual activity for 24 hours, as these can raise prolactin.