Insulin is a peptide hormone produced by pancreatic beta cells that regulates glucose metabolism and cellular energy storage. Fasting insulin levels reflect the body's baseline insulin production and can indicate insulin resistance when elevated, a key feature of metabolic dysfunction and type 2 diabetes risk. Insulin facilitates glucose uptake into cells, promotes glycogen synthesis in liver and muscle, and inhibits lipolysis while promoting lipogenesis. In the fasting state, insulin levels should be low as glucose homeostasis is maintained through hepatic glucose production and minimal peripheral glucose uptake.
Fasting insulin measures the basal output of insulin from pancreatic beta cells. It is one of the earliest detectable markers of insulin resistance, often becoming elevated years before fasting glucose or HbA1c rise above normal. Paired with fasting glucose, it enables calculation of HOMA-IR (homeostatic model assessment of insulin resistance).
Elevated fasting insulin (generally >10-15 µIU/mL, lab-dependent) indicates that the pancreas is producing more insulin than normal to maintain euglycemia — a hallmark of insulin resistance. Very low levels may indicate beta-cell dysfunction or type 1 diabetes. Insulin levels vary significantly with fasting duration, stress, and recent carbohydrate intake.
Exercise acutely improves insulin sensitivity by increasing glucose transporter (GLUT4) translocation to the cell membrane independent of insulin signaling. However, sleep deprivation, psychological stress, and high-cortisol states can impair insulin sensitivity even in highly trained individuals. Fasting insulin tracked alongside glucose provides a more complete picture of metabolic efficiency than glucose alone.
Turnaround Time
3 days (up to 12 days)
Fasting
Recommended
Method
Electrochemiluminescence immunoassay (ECLIA)
Order online
Choose your lab and check out. We send your lab requisition automatically — no doctor visit needed.
Get your sample collected
Visit a lab service center near you for a quick blood draw (or book at-home phlebotomy where available).
See your results
Your results land in your Insider portal, ready to review and act on — that easy.
Your price
$3.90$70
17.9× less than retail
Versus the typical direct-to-consumer retail price for this test (illustrative — consumer prices vary by provider and region).
$3.90
$9.90
$17.90
Peer-reviewed sources supporting the educational content on this page.
Insulin is a peptide hormone produced by pancreatic beta cells that regulates glucose metabolism and cellular energy storage. Fasting insulin levels reflect the body's baseline insulin production and can indicate insulin resistance when elevated, a key feature of metabolic dysfunction and type 2 diabetes risk.
Fasting insulin measures the basal output of insulin from pancreatic beta cells. It is one of the earliest detectable markers of insulin resistance, often becoming elevated years before fasting glucose or HbA1c rise above normal.
Elevated fasting insulin (generally >10-15 µIU/mL, lab-dependent) indicates that the pancreas is producing more insulin than normal to maintain euglycemia — a hallmark of insulin resistance. Very low levels may indicate beta-cell dysfunction or type 1 diabetes.
The Insulin test starts at $3.90 at Labcorp, Quest, or BioReference. No doctor's visit and no insurance needed; we do not bill insurance. Fitomics Insider members pay from $3.50.
Fasting is recommended before the Insulin test: fast 9 to 12 hours beforehand (water is fine) so the results are usable. This is not a requirement; it is your choice.
Results for the Insulin test are typically ready about 3 days after your draw, and up to 12 days for some samples. Your results land in your Insider portal.
No. When you order the Insulin test from Fitomics Research Labs, a licensed physician in our 50-state network reviews and signs your requisition after checkout, and it lands in your portal and inbox. Then visit any Labcorp, Quest, or BioReference patient service center for your draw; results post to your Insider portal.
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