Heart & metabolic

Fasting insulin test

Fasting insulin shows how hard your pancreas works to keep blood sugar steady.

Included in every $199 draw

Key benefits of fasting insulin testing

Flags insulin resistance years before glucose or A1C rise.
Explains energy crashes, cravings and stubborn belly fat.
Combines with glucose to calculate HOMA-IR.
Tracks how fast diet, sleep and exercise changes are working.
Not part of most standard checkups.

What is insulin?

Insulin is the hormone that moves sugar from your blood into your cells. When cells stop responding well, your pancreas makes more insulin to keep glucose normal.

Why fasting insulin matters

High insulin keeps blood sugar looking normal for years while the problem grows underneath. It's linked to weight gain, fatty liver, high triglycerides, PCOS and higher heart risk.

What your fasting insulin results mean

Low: usually healthy if glucose is normal. Very low insulin with high glucose needs a physician review.
In range: your cells respond well to insulin.
High: a sign of insulin resistance, even if glucose and A1C look normal.
Context matters: you must fast 8 to 12 hours, or the result will read falsely high.

Standard vs. optimal range

	Range
Standard lab range	Varies by lab; roughly 2 to 25 µIU/mL
Insyght optimal range	Set by the Insyght medical team

LowHigh

Lab reference rangeYour optimal range

A value can read normal on a standard panel and still sit outside optimal. Insyght flags it.

Do I need a fasting insulin test?

Hungry soon after eating, sleepy after carbs, or gaining weight despite effort? Fasting insulin shows what your glucose number hides.

See the problem before your glucose does

Insyght tests fasting insulin, glucose and A1C together, so your physician sees the full metabolic picture. $199 a year.

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Similar biomarkers

Hemoglobin A1cGlucoseTriglyceridesTriglyceride/HDL RatioUric Acid

Frequently asked questions

What is HOMA-IR?

HOMA-IR combines fasting insulin and fasting glucose into one score for insulin resistance. Higher scores mean more resistance.

Can I have insulin resistance with a normal A1C?

Yes. Insulin often rises first to keep glucose normal. That's why testing insulin catches it earlier.

How can I lower fasting insulin?

Regular exercise, strength training, good sleep and fewer refined carbs all help. Your physician can tailor a plan to your results.

Medically reviewed by Dr. Maria Gutierrez Horn, MD, FACE, Board-certified endocrinologist, in practice since 2001. Last updated September 28, 2026.