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Thyroid Stimulating Hormone (TSH) with Serum Protein Correction

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

This test measures your thyroid-stimulating hormone (TSH) level after accounting for potential interference from certain proteins in your blood.

Quick summary

["A more accurate way to assess thyroid function by adjusting for protein effects that might otherwise affect test results."]

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

Key facts at a glance

LOINC
50535-4
Short code
TSH sp3 SerPl-aCnc
Synonyms
TSH sp3 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
84443
SNOMED
301343003
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 thyroid issues, such as hypothyroidism (underactive thyroid) or hyperthyroidism (overactive thyroid), especially if your initial TSH test results seem unusually high or low despite normal protein levels. It can also help confirm diagnoses or monitor treatment progress in thyroid disorders.

What to Expect Before the Test

No special preparation is needed for this test. You may have a blood draw from a vein in your arm, similar to other blood tests. It usually takes a few minutes, and you can resume normal activities afterward.

What the Results Mean

TSH levels help determine whether your thyroid is working properly. While this test corrects for protein interference, your doctor will interpret results in the context of your overall health and symptoms. Abnormal results may prompt further testing or follow-up.

Common Reasons for Testing

This test is often used when initial TSH results are unclear due to potential protein-related errors, such as in patients with certain genetic conditions, severe infections, or extreme stress. It ensures more reliable thyroid function assessment.

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

TSH with Protein Correction

Frequently asked questions

What does a high or low TSH level with protein correction indicate?
A corrected TSH result may still be outside reference ranges if thyroid disease is present, but it helps rule out protein-related artifacts that could otherwise mislead diagnosis. Your doctor will discuss findings with you and may recommend additional tests if needed.
How does protein correction differ from standard TSH testing?
Protein correction adjusts for substances in your blood that could bind to TSH antibodies or interfere with the test, providing a more accurate measurement. Standard TSH tests may not account for these factors, so correction is useful in specific clinical scenarios.
Can I fast before this test?
No fasting is required for this test. However, always follow your doctor’s instructions, as some tests may have specific guidelines for timing or activity.
  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