Fasting Insulin · high result
What does a high Fasting Insulin mean?
Short answer
High fasting insulin means the pancreas is working harder to keep glucose normal — the hallmark of insulin resistance, which precedes prediabetes and type 2 diabetes by years. Excess weight (especially abdominal), inactivity, poor sleep, PCOS, fatty liver and some medications drive it. A non-fasting sample raises insulin dramatically, so the fast has to be real.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
What is the normal range for Fasting Insulin?
- age 18+, fasting: 2.00 – 20.0 uIU/mL
Often reflects insulin resistance, prediabetes, or PCOS.
Full reference table, citations and testing options: Fasting Insulin biomarker page.
What are the common causes of high Fasting Insulin?
- Not fasting
- Insulin resistance from excess weight, inactivity, poor sleep
- PCOS
- Non-alcoholic fatty liver disease
- Medications: glucocorticoids, some antipsychotics
- Rare: insulinoma (with low glucose)
What symptoms go with high Fasting Insulin?
- Often none
- Weight gain around the middle, hunger soon after eating, afternoon energy crashes
- Skin tags, darkened skin folds (acanthosis nigricans)
What do clinicians usually check next?
- Fasting glucose and A1c (HOMA-IR can be calculated from glucose and insulin)
- Lipid panel and liver enzymes
- Repeat fasting if timing was uncertain
Follow-up tests available at TestWell: Lipid Panel ($24.99), Glucose ($14.99).
How do you recheck Fasting Insulin?
Prices are cash-pay; every order adds one $6 lab processing fee. Physician authorization is included; no insurance or referral needed.
| Test or panel | Type | Price | Fasting | Results |
|---|---|---|---|---|
| Diabetes Screening Panel | Panel · 3 tests | $59.99 | Yes | 2–5 business days |
| Pre-Diabetes Panel | Panel · 5 tests | $89.99 | Yes | 2–5 business days |
| Metabolism & Weight Loss Panel | Panel · 8 tests | $119.99 | Yes | 2–5 business days |
| Insulin, Fasting | Test | $22.99 | Yes | 2–4 business days |
Common questions
What fasting insulin level is high?
Reference ranges go up to about 25 µIU/mL, but many clinicians consider values above 10–15 a sign of insulin resistance, especially with a HOMA-IR above about 2.5.
Sources
Educational content, not a diagnosis. Lab results are one input; a clinician interprets them with your history and exam.