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Total Salivary Thyroxine (T4) Mass Concentration

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

This test measures the amount of thyroxine (T4), a hormone produced by your thyroid gland, in your saliva. Salivary T4 can help assess thyroid function, especially in people who may have difficulty with blood tests or prefer a non-invasive sample.

Quick summary

["Salivary T4 helps monitor thyroid hormone levels in a simple, painless way."]

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

Key facts at a glance

LOINC
27000-9
Short code
T4 Sal-mCnc
Synonyms
T4 Sal-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
4.5
Ref high
12
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84436
SNOMED
302345006
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 Is This Test Done?

Your healthcare provider may recommend a salivary T4 test if you have symptoms like fatigue, weight changes, or mood swings that might suggest thyroid issues. It’s also useful for people who cannot or prefer not to have blood drawn, such as children, elderly individuals, or those with vein difficulties. Salivary testing can sometimes provide results more quickly than blood tests.

How Is the Sample Collected?

You’ll chew on a special cotton swab for a few seconds to collect saliva, then spit it into a container. No needles or blood are involved. The sample is then sent to a lab for analysis.

What Does the Result Mean?

Salivary T4 results are interpreted based on your overall health, symptoms, and other tests. While reference ranges can vary by lab, very low or very high levels may signal potential thyroid dysfunction. Your provider will discuss the results in the context of your medical history and other tests.

What Are Common Causes of Abnormal Results?

Low salivary T4 may indicate hypothyroidism (underactive thyroid), while high levels could suggest hyperthyroidism (overactive thyroid). Other factors, like stress, medications, or recent illness, can also affect results.

Reference range

Adult: 4.5-12.0 μg/dLN/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.

◆Associated findings1

Short name

Total Salivary T4

Frequently asked questions

How often will I need this test?
The frequency depends on your health status and symptoms. If you have a known thyroid condition, your provider may recommend testing every few months or as needed. If this is a one-time screening, results may not require follow-up unless they’re outside expected ranges.
What if my salivary T4 is outside the normal range?
If your results are abnormal, your provider will likely order additional tests (like blood TSH or free T4) to confirm or explore the cause. They may also adjust medications or recommend lifestyle changes to help manage symptoms.
Can I eat or drink before this test?
You can eat and drink normally before the test, as it doesn’t require fasting. Avoiding caffeine or strong minty mouthwash for a few hours before collection may help ensure accurate results.
  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