Insulin
The hormone that regulates blood sugar — often elevated long before fasting glucose changes.
What is it
Fasting insulin measures circulating insulin after an overnight fast. It is one of the earliest markers to change when insulin resistance begins to develop.
Why it's measured
Elevated fasting insulin has been associated with insulin resistance and metabolic syndrome features in research literature, often years before fasting glucose rises.
Reference range
Standard laboratory reference
< 10 μIU/mL
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Has been associated with insulin resistance and elevated cardiometabolic risk in published research.
Lower
Is generally considered favorable in research on metabolic health.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Not routinely included in standard physicals — often ordered when investigating metabolic dysfunction.
Related markers
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Explore the Apex Panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.