Prolactin blood test
Quick answer: A prolactin test measures prolactin, a hormone from the pituitary gland that helps produce breast milk. It is ordered for irregular or missed periods, unexpected breast milk, infertility, low sex drive or erection problems, and headaches or vision problems that suggest a pituitary issue.
- SampleBlood
- TakesAbout 5 to 10 minutes, including rest
- Before the testA morning sample taken after resting is often preferred; tell staff about any medicines you take, as some raise prolactin.
- In fertility careHigh prolactin can stop ovulation, so it is commonly checked when periods are irregular or when trying to conceive.
How the test is done
- 1You may be asked to come in the morning and rest quietly for a while first
- 2A vein in your arm is cleaned
- 3Blood is drawn gently, as stress from the needle can raise prolactin slightly
- 4If the result is high, a repeat sample may be taken after resting
What your results can mean
Reading your report
Stress, sleep, recent meals and some medicines can raise prolactin, so a mildly high result is often repeated; discuss it with your doctor.
If the result is outside the usual range
A high level can be seen with stress, sleep, pregnancy and breastfeeding, an underactive thyroid, some medicines, or a benign pituitary growth called a prolactinoma. A low level is uncommon and rarely causes problems.
Who usually has this test
Women with irregular or missed periods, breast milk when not breastfeeding, or difficulty getting pregnant, and men with low sex drive or erection problems.
Risks and aftercare
You can leave straight away; a slight bruise is possible where the needle went in.
Names and options
Also called: serum prolactin, PRL test
Listed by the hospital as
- PROLACTIN, SERUM
Where this test fits in fertility care
- 1Fertility work-upThis test
- 2Screening before IVF or IUI
- 3During treatment
- 4After embryo transfer
- 5Pregnancy check-ups
- 6If treatment has not worked
The usual order. See every test at each stage →
Questions about this test
Can high prolactin cause infertility?
Yes. High prolactin can interfere with ovulation and cause irregular or absent periods. It is usually treatable with medicine once the cause is found.
Do I need to fast for a prolactin test?
Fasting is not usually required. Many labs prefer a sample taken in the morning a few hours after waking, after sitting quietly for a while, because stress and exercise can raise the level.
What is macroprolactin?
Macroprolactin is a large, less active form of prolactin that can make the result look high even though it does not cause symptoms. If your prolactin is raised without symptoms, the lab may check for macroprolactin.
Related tests
Tamara Hospital & IVF Centre, Rajajinagar
34/3, 10th Cross Road, opp. Vardhaka Sardar Patel School, 1st N Block, 2nd Stage, Rajajinagar, Bengaluru 560010
The hospital is open 24 hours. Call before you come to check the timing for your scan or sample collection.
Get directions ↗IVF Pulse fertility care at Tamara Hospital →
Reception
Waiting area
IVF lab
This page explains each test in general terms so you know what to expect. It is not medical advice: your doctor decides which tests you need and what your results mean. Reference ranges differ between laboratories. Updated 4 November 2026.