Selenium levels: what's normal, high and low
An antioxidant trace mineral important for thyroid function and immune health.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
Selenium is measured with a standard blood draw; no fasting is needed. A typical reference range is 70.0 – 150 mcg/L. At TestWell it's $64.99 all-in as Selenium, results in 3–7 business days, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis.
- Units
- mcg/L / ug/L
- Sample
- Blood draw
- Fasting
- Not required
- Results
- 3–7 business days
- Price
- $64.99
- Labs
- Quest or Labcorp
Selenium 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+ | 70.0 – 150 mcg/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 Selenium result may mean
Can reflect malabsorption or low-selenium diets in certain regions.
What a low Selenium 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 Selenium test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. Selenium is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| Selenium | This marker only | $64.99 |
| Vitamin & Mineral Deficiency Panel | 9 tests | $189.99 |
| Women's Hair Health Panel | 19 tests | $469.99 |
| Total Body Panel | 49 tests | $499.99 |
| Men's Hair Health Panel | 19 tests | $499.99 |
Quest vs. Labcorp for Selenium: 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 | $64.99 |
| Labcorp | Yes | $77.99 |
| BioReference (NY & NJ) | No | — |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
Frequently asked
Can reflect malabsorption or low-selenium diets in certain regions. A single result below 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 selenium?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $64.99.