Thyroid Stimulating Hormone (TSH) with Triple Stimulation Test (Serum)
This test measures your thyroid-stimulating hormone (TSH) levels after receiving three doses of thyroid hormone to check how your body responds. It helps evaluate whether your thyroid gland is functioning normally or if it’s underactive (hypothyroidism) or overactive (hyperthyroidism).
This test helps diagnose and monitor thyroid disorders by assessing how your pituitary gland responds to thyroid hormone stimulation.
Key facts at a glance
- LOINC
- 40397-2
- Short code
- TSH 15M p Triple Bolus SerPl-aCnc
- Synonyms
- TSH 15M p Triple Bolus SerPl-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.4
- Ref high
- 4
- Critical range
- 0.1 N/A – 20 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 recommend this test if you have symptoms like fatigue, weight changes, or unexplained thyroid issues. It’s also used to confirm or rule out conditions like hypothyroidism or hyperthyroidism, especially when standard TSH tests are inconclusive.
How the Test Works
You’ll receive three doses of synthetic thyroid hormone (levothyroxine) over a few days. Blood samples are taken before and after each dose to measure your TSH levels. This helps determine how well your pituitary gland adjusts to the hormone.
What to Expect Before the Test
No special preparation is needed, but inform your doctor about any medications (especially thyroid-related ones) or health conditions you have. Avoid smoking or caffeine before testing if advised.
What to Expect During the Test
A blood sample is drawn from a vein in your arm. It’s quick and usually painless, though you might feel a slight pinch. The test itself takes a few minutes, and you can return to your normal activities afterward.
Reference range
Adult: 0.4-4.0 mIU/LN/A
Take your thyroid medication after the blood draw if applicable. No fasting required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal results can indicate thyroid dysfunction. Low TSH after stimulation may suggest hypothyroidism, while high TSH could indicate resistance or other pituitary issues. This test helps refine diagnosis and guide treatment plans, such as adjusting thyroid hormone doses.
Short name
Triple Stimulation TSH Test
Frequently asked questions
What does a normal result mean?
How long does it take to get results?
Can I take thyroid medication 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