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Thyroid Stimulating Hormone (TSH) with Triple Stimulation Test (Serum/Plasma)

Published: August 9, 2026Updated: August 16, 2026

This test measures your thyroid-stimulating hormone levels after receiving three doses of thyroid hormone to check how your thyroid responds. It helps diagnose or monitor conditions like hypothyroidism or thyroid resistance.

Quick summary

["Assesses how well your thyroid gland responds to thyroid hormone stimulation over time."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
40398-0
Short code
TSH 1h p Triple Bolus SerPl-aCnc
Synonyms
TSH 1h 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 order this test if they suspect an issue with your thyroid’s ability to respond normally to thyroid-stimulating hormone (TSH). Common reasons include unexplained symptoms of hypothyroidism, resistance to thyroid hormone, or evaluating treatment effectiveness for thyroid conditions.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before testing. Bring any medications you’re currently taking, as they could affect results.

What Happens During the Test

Blood is drawn from a vein in your arm. You may feel a slight pinch, but it usually takes only a few minutes. The sample is sent to a lab for analysis after receiving three doses of synthetic thyroid hormone.

What the Results Mean

Results show how your TSH levels change after stimulation. Abnormal patterns may indicate conditions like thyroid resistance (e.g., Riedel’s thyroiditis) or other thyroid dysfunctions. Your doctor will interpret results in the context of your symptoms and medical history.

Reference range

Adult: 0.4-4.0 mIU/LN/A

Specimen: serum

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.

Clinical Significance

Short name

Triple Stimulation TSH Test

Frequently asked questions

What symptoms might this test be used for?
This test is often used if you have symptoms like fatigue, weight changes, or unexplained thyroid dysfunction, even if your initial TSH test results are unclear. It helps distinguish between normal resistance to thyroid hormone and true hypothyroidism.
How is this test different from a standard TSH test?
Unlike a standard TSH test, which measures baseline hormone levels, this test evaluates how your body reacts to synthetic thyroid hormone. It provides a clearer picture of thyroid responsiveness over time.
Will I need to take any special steps after the test?
No special follow-up is required unless your doctor requests additional testing or monitoring. Results may take several days to review, so discuss any concerns with your healthcare provider.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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