Fasting insulin measures how much insulin your pancreas produces to control blood sugar - an early warning sign of metabolic problems.
Insulin is the hormone that moves glucose from your blood into your cells. When cells become resistant to insulin, your pancreas has to produce more to keep blood sugar normal. This "hyperinsulinemia" can exist for years before blood sugar rises and diabetes develops.
Testing fasting insulin catches metabolic dysfunction early, when lifestyle changes are most effective. It's a key marker in understanding your metabolic health beyond just blood sugar.
Price
$14
Results
1-2 days
Lab Network
Quest
Fasting
10+ hrs
What's Measured
What This Test Measures
This test measures the amount of insulin in your blood after fasting. Normal fasting insulin is typically 2-25 µIU/mL, with optimal levels below 10 µIU/mL. Higher levels suggest insulin resistance, even if blood sugar is still normal.
Who Should Consider This Test
Anyone with risk factors for diabetes (family history, overweight, PCOS, sedentary lifestyle), those with metabolic syndrome, people with high triglycerides or low HDL, and anyone wanting a deeper understanding of their metabolic health.
Health Insights
Conditions Screened
Related Symptoms
When to Get Tested
Test after fasting 10-12 hours. Best done in the morning. Can be combined with fasting glucose to calculate HOMA-IR (insulin resistance index).
Fasting Required
This test requires fasting for accurate results. Please follow these instructions:
- Do not eat or drink anything except water for 10-12 hours before your blood draw.
- Water is allowed and encouraged - stay hydrated!
- Schedule your lab visit in the morning for convenience.
- Continue taking any prescribed medications unless advised otherwise by your doctor.
Understanding Your Results
Optimal fasting insulin is below 10 µIU/mL. Levels of 10-25 may indicate early insulin resistance. Above 25 suggests significant insulin resistance. When combined with fasting glucose, your results can be used to calculate HOMA-IR for a more complete picture.
What to Expect
After placing your order, you'll receive an email from Rupa Health (our lab order partner) within 24 business hours to sign a consent form and schedule your blood draw at a Quest Diagnostics location.
The blood draw typically takes just a few minutes. Results are usually available within 1-2 business days and will appear in your secure Justlabs dashboard.
Our results include reference ranges and easy-to-understand indicators showing whether your values are within normal limits.
Frequently Asked Questions
$14
Typical hospital cash price: $150–$250
+ $28 in standard lab & physician fees at checkout (no additional bills later)
$18 lab collection + $10 physician order
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