Prolactin level measured 2 hours post-recombinant human growth hormone (rhGH) stimulation via serum/plasma
This test checks how your body responds to a growth hormone trigger by measuring prolactin levels in your blood after 2 hours.
["Helps diagnose conditions affecting hormone balance or pituitary function."]
Key facts at a glance
- LOINC
- 44930-6
- Short code
- Prolactin 2h p TRH IV SerPl-aCnc
- Synonyms
- Prolactin 2h p TRH IV SerPl-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your doctor may order this test if they suspect a pituitary gland issue, such as a tumor or disorder that affects hormone production. It can also help evaluate conditions like hyperprolactinemia or growth hormone deficiency.
What to Expect Before the Test
You’ll receive a growth hormone injection (rhGH) at the clinic. Blood will be drawn just before and again 2 hours later to check prolactin levels. Avoid caffeine or stress before testing as it may affect results.
What Happens During the Test
A healthcare provider will draw blood from a vein in your arm. You may feel slight discomfort, but it’s usually over quickly. The blood sample will be sent to a lab for analysis.
What the Results Mean
Results compare your prolactin level before and after the injection. Elevated levels after stimulation may indicate a pituitary issue or other hormonal problems. Your doctor will discuss findings with you.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Prolactin is a hormone produced by the pituitary gland that regulates milk production and affects other hormones. Elevated prolactin levels can cause infertility, irregular periods, or symptoms like headaches. Low levels may suggest growth hormone deficiency or other pituitary disorders. This test helps diagnose these conditions by assessing how prolactin responds to a growth hormone trigger.
Short name
Prolactin after rhGH test
Frequently asked questions
What does a prolactin level after rhGH stimulation tell me about my health?
How long will I need to wait for my results?
Can I take anything special before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy