Fasting Insulin levels: what's normal, high and low
How much insulin your pancreas is releasing at rest. High values often indicate insulin resistance.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
Fasting Insulin is measured with a standard blood draw after an 8–12 hour fast. A typical reference range is 2.00 – 20.0 uIU/mL. At TestWell it's $22.99 all-in as Insulin, Fasting, results in 2–4 business days, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis.
- Units
- uIU/mL / µIU/mL
- Sample
- Blood draw
- Fasting
- 8–12 hours
- Results
- 2–4 business days
- Price
- $22.99
- Labs
- Quest or Labcorp · BioReference in NY/NJ
Fasting Insulin 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+, fasting | 2.00 – 20.0 uIU/mL |
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 Fasting Insulin result may mean
Often reflects insulin resistance, prediabetes, or PCOS.
What a high Fasting Insulin 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 Fasting Insulin test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. Fasting Insulin is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| Insulin, Fasting | This marker only | $22.99 |
| Diabetes Screening Panel | 3 tests | $59.99 |
| Pre-Diabetes Panel | 5 tests | $89.99 |
| Metabolism & Weight Loss Panel | 8 tests | $119.99 |
| GLP-1 Monitoring & Weight Management | 10 tests | $169.99 |
Quest vs. Labcorp for Fasting Insulin: 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 | $22.99 |
| Labcorp | Yes | $23.99 |
| BioReference (NY & NJ) | Yes | $23.99 |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
Related Diabetes & Blood Sugar biomarkers
Markers commonly tested alongside Fasting Insulin.
Frequently asked
Often reflects insulin resistance, prediabetes, or PCOS. 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 fasting insulin?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $22.99.