TSH levels: what's normal, high and low
A pituitary hormone that signals your thyroid. The most sensitive screen for thyroid problems.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
TSH is measured with a standard blood draw; no fasting is needed. A typical reference range is 0.450 – 4.50 mIU/L (age 18+; more bands below). At TestWell it's $26.99 all-in as TSH (Thyroid Stimulating Hormone), results in 1–3 business days, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis.
- Units
- mIU/L / uIU/mL
- Sample
- Blood draw
- Fasting
- Not required
- Results
- 1–3 business days
- Price
- $26.99
- Labs
- Quest or Labcorp · BioReference in NY/NJ
TSH Reference Range
These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.
| Population | Range |
|---|---|
| age 18+ | 0.450 – 4.50 mIU/L |
| age 18+, pregnancy | 0.100 – 4.00 mIU/L |
Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.
What your TSH result may mean
Often reflects an underactive thyroid (hypothyroidism); medications and recovery from illness can also raise TSH.
What a high TSH means: causes, symptoms, next steps →Often reflects an overactive thyroid (hyperthyroidism), excess thyroid medication, or pituitary issues.
What a low TSH means: causes, symptoms, next steps →Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.
How do you get a TSH test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. TSH is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| TSH (Thyroid Stimulating Hormone) | This marker only | $26.99 |
| Essential Thyroid Panel | 3 tests | $79.99 |
| General Wellness Panel | 4 tests | $89.99 |
| Post-COVID Recovery Panel | 7 tests | $99.99 |
| Erectile Dysfunction Panel | 7 tests | $114.99 |
Quest vs. Labcorp for TSH: which lab should you pick?
Both are CLIA-certified national labs and the result is clinically equivalent, so pick whichever location is closer. Your report will print that lab's own reference range, which can differ slightly from the table above.
| Lab | Available | Price |
|---|---|---|
| Quest Diagnostics | Yes | $26.99 |
| Labcorp | Yes | $27.99 |
| BioReference (NY & NJ) | Yes | $24.99 |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
How often should you retest TSH?
If you take levothyroxine, recheck TSH about 6–8 weeks after any dose change — it takes that long for the level to settle — and then every 6–12 months once stable, per the American Thyroid Association. Without known thyroid disease there's no fixed interval; a repeat is reasonable when symptoms change or a first result was borderline.
General guidance from the sources listed below — your clinician may set a different schedule based on your history and results.
Related Thyroid biomarkers
Markers commonly tested alongside TSH.
Frequently asked
Often reflects an underactive thyroid (hypothyroidism); medications and recovery from illness can also raise TSH. A single result above the reference range is a prompt to look closer with a clinician — often a repeat test and related markers — not a diagnosis on its own.
Ready to test your tsh?
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