What does HOMA-IR measure?

HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) estimates insulin resistance from two fasting blood values: glucose and insulin. It reflects how hard the pancreas must work (i.e., how much insulin it must secrete) to maintain a given fasting glucose level. A higher HOMA-IR means more insulin is needed for a given glucose — the hallmark of insulin resistance.

How is HOMA-IR calculated?

The original HOMA-IR formula uses glucose in mmol/L: HOMA-IR = (fasting insulin [µIU/mL] × fasting glucose [mmol/L]) / 22.5. For glucose in mg/dL, the adapted formula is: HOMA-IR = (fasting insulin [µIU/mL] × fasting glucose [mg/dL]) / 405. Both formulas are equivalent; the denominator adjustment accounts for the unit conversion (1 mmol/L glucose = 18 mg/dL).

What is QUICKI and how does it compare to HOMA-IR?

QUICKI (Quantitative Insulin Sensitivity Check Index) = 1 / (log10[fasting insulin] + log10[fasting glucose]). It uses the same two inputs as HOMA-IR but produces a result that scales inversely — higher QUICKI means better insulin sensitivity (unlike HOMA-IR where higher means worse). Both correlate well with the gold-standard euglycemic hyperinsulinemic clamp (r ≈ 0.85–0.90). QUICKI is slightly preferred in some studies for its logarithmic transformation, which normalizes the skewed distribution of insulin values.

When is HOMA-IR clinically useful?

HOMA-IR is most useful for: evaluating insulin resistance in patients with metabolic syndrome or PCOS; screening for pre-diabetic insulin resistance before glucose becomes abnormal; assessing NAFLD severity (correlates with hepatic steatosis); monitoring response to lifestyle interventions or insulin-sensitizing medications; and research studies comparing insulin resistance across populations or treatment arms. It is not useful in type 1 diabetes or after pancreatectomy.

Can HOMA-IR be used in children?

Yes, HOMA-IR is used in pediatric metabolic research and can be applied in clinical practice for children with obesity or suspected metabolic syndrome. However, reference ranges differ from adults. Pubertal children normally have higher insulin levels and HOMA-IR values; published pediatric-specific percentile references should be used. Adult cutoffs (2.0–2.5) should not be directly applied to children, especially adolescents during puberty.

Does metformin lower HOMA-IR?

Yes. Metformin reduces insulin resistance primarily by decreasing hepatic glucose production (gluconeogenesis), which in turn reduces the insulin needed to maintain fasting glucose. Clinical trials show metformin reduces HOMA-IR by approximately 20–30% over 3–6 months. This effect is the basis for its use in diabetes prevention, PCOS treatment, and NAFLD management. Other insulin-sensitizing agents (pioglitazone, GLP-1 agonists) have even larger effects on HOMA-IR.

Is HOMA-IR the gold standard for measuring insulin resistance?

No. The gold standard for measuring insulin resistance is the euglycemic hyperinsulinemic clamp technique, which directly quantifies glucose uptake under controlled insulin and glucose infusion conditions. HOMA-IR is a validated surrogate that correlates well with the clamp (r ≈ 0.88 in the original Matthews et al. validation study) but is estimated from fasting steady-state values rather than dynamic testing. It is suitable for clinical and epidemiological use but cannot fully replace the clamp in research requiring precise insulin sensitivity measurement.

Online Medical Tools — HOMA-IR

Printed on 9/2/2026

For informational purposes only. This is not medical advice.

Endocrinology

HOMA-IR

HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) uses fasting glucose and fasting insulin to estimate insulin resistance. Higher values suggest lower insulin sensitivity and are often used in metabolic risk evaluation.

Formula: HOMA-IR = (Fasting Insulin [uIU/mL] x Fasting Glucose [mg/dL]) / 405.

Fasting Glucose

mg/dL

Fasting Insulin

uIU/mL

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How It Works

Obtain fasting labs

HOMA-IR requires a true fasting blood draw (8–12 hours of fasting, no food or caloric beverages). Both fasting glucose and fasting insulin must be measured from the same morning fasting sample. Glucose is measured in mg/dL and insulin in µIU/mL (microinternational units per milliliter).

Enter fasting glucose and fasting insulin

Input your fasting glucose (mg/dL) and fasting insulin (µIU/mL). The calculator uses the HOMA-IR formula adapted for mg/dL units: HOMA-IR = (fasting insulin × fasting glucose) / 405. The divisor 405 converts glucose from mg/dL to mmol/L equivalents used in the original Matthews et al. formula.

Interpret your HOMA-IR result

Results below 1.0 are optimal insulin sensitivity. The range 1.0–2.9 represents normal to mildly elevated, with values above 2.0 raising concern for early insulin resistance in many Western populations. A HOMA-IR above 2.9 suggests significant insulin resistance. Cutoffs are population-specific; South Asian individuals may have clinically significant insulin resistance at lower values.

Who Uses the HOMA-IR

Metabolic Syndrome Evaluation

Internists, endocrinologists, cardiologists

Quantify insulin resistance as part of metabolic syndrome assessment (alongside abdominal obesity, hypertriglyceridemia, low HDL, and elevated blood pressure). HOMA-IR provides a more direct measure of insulin resistance than any single metabolic criterion and strengthens the overall picture.

PCOS Screening and Monitoring

Gynecologists, reproductive endocrinologists

Estimate insulin resistance in polycystic ovary syndrome (PCOS), where 50–70% of women have insulin resistance independent of BMI. A HOMA-IR above 2.5 is often used as a threshold in PCOS. Guides decisions about metformin therapy and lifestyle interventions.

Prediabetes Risk Assessment

Primary care, preventive medicine

Identify patients with prediabetes who have insulin resistance as the primary driver. HOMA-IR can be elevated even when fasting glucose is still normal, making it an earlier indicator of metabolic dysfunction than glucose alone.

NAFLD/MASLD Staging

Hepatologists, gastroenterologists

Assess insulin resistance in non-alcoholic fatty liver disease (NAFLD) / metabolic dysfunction-associated steatotic liver disease (MASLD). HOMA-IR correlates with hepatic steatosis severity and is used in non-invasive staging scores. Elevated HOMA-IR is associated with progression to NASH.

Monitoring Lifestyle Intervention Response

Endocrinologists, dietitians, exercise physiologists

Track improvements in insulin sensitivity over time in response to weight loss, dietary changes, or exercise programs. A 5–7% reduction in body weight often reduces HOMA-IR by 20–40%, providing objective evidence of metabolic improvement even when glucose remains normal.

Pro Tips

Must be truly fasting — 8–12 hours, no food or caloric beverages

Even a small snack or coffee with milk can spike insulin levels significantly, dramatically elevating HOMA-IR and creating a falsely high result. Instruct patients to fast overnight and come for the blood draw before breakfast. Water is acceptable. A non-fasting sample renders the result uninterpretable.

Insulin assay variability makes absolute cutoffs less reliable

Different laboratories use different insulin assay methods (RIA, ECLIA, CLIA) that are not standardized, leading to systematic differences in insulin values — sometimes by 20–30%. Absolute HOMA-IR cutoffs (e.g., 2.0) established in one study may not directly apply to another lab's assay. Serial measurements within the same lab are more meaningful than single values against published thresholds.

South Asian populations may have insulin resistance at lower HOMA-IR values

South Asian individuals often develop metabolic complications at lower BMI and lower HOMA-IR values than Western European populations. Some studies suggest HOMA-IR thresholds of 1.5–2.0 may be more appropriate for South Asian patients. Ethnic-specific reference ranges should be applied when available.

PCOS often shows HOMA-IR above 2.5

Women with PCOS frequently have HOMA-IR values in the 2.5–5.0 range even without obesity. Insulin resistance in PCOS contributes to hyperandrogenism, anovulation, and cardiovascular risk. Metformin improves insulin sensitivity and is often initiated when HOMA-IR is elevated in this context.

Pair HOMA-IR with TyG index and lipid ratios for a fuller metabolic picture

The Triglyceride-Glucose (TyG) index = ln[triglycerides (mg/dL) × fasting glucose (mg/dL) / 2] provides a complementary insulin resistance estimate that doesn't require fasting insulin. The non-HDL/HDL cholesterol ratio and triglyceride/HDL ratio also correlate with insulin resistance. Using multiple markers increases confidence in the assessment.

5–7% weight loss often reduces HOMA-IR by 20–40%

In overweight and obese patients, modest intentional weight loss has a disproportionately large effect on insulin resistance. A 5–7% body weight reduction — the minimum recommended by diabetes prevention programs — consistently reduces HOMA-IR by 20–40% in clinical trials. This is a powerful motivational statistic for patient counseling.

HOMA-IR does not diagnose diabetes — it estimates insulin resistance

HOMA-IR is a research and clinical risk-stratification tool, not a diagnostic test for diabetes or prediabetes. Diabetes diagnosis requires HbA1c, fasting glucose, or oral glucose tolerance test (OGTT) by established criteria. A high HOMA-IR with normal glucose indicates pre-diabetic insulin resistance, not diabetes itself.

Insulin resistance can be present with a completely normal fasting glucose

In early insulin resistance, the pancreas compensates by secreting more insulin to maintain normal fasting glucose. This results in a high HOMA-IR (high insulin × normal glucose) but a normal fasting glucose. HOMA-IR can detect this compensated state years before glucose rises above normal, making it a useful early screening tool.

Exercise improves HOMA-IR independent of weight loss

Regular aerobic exercise and resistance training both reduce insulin resistance through mechanisms independent of weight change — including improved skeletal muscle glucose uptake and reduced hepatic glucose output. Patients who maintain weight but increase physical activity show meaningful HOMA-IR reductions, reinforcing exercise as a first-line intervention.

Common Questions About Your Results

This is the classic early insulin resistance pattern: compensated hyperinsulinemia. The pancreas is working overtime to maintain normal glucose by secreting excess insulin. HOMA-IR captures this because it incorporates the insulin level, not just glucose. This stage often precedes impaired fasting glucose by years and is an important early intervention window. Focus on lifestyle changes: weight loss, exercise, reduced refined carbohydrates.

Fasting insulin is not a standard panel item at many labs. You may need to specifically request it, or have it run at a reference laboratory. Some insurance plans do not cover fasting insulin without specific documentation of need (e.g., PCOS, metabolic syndrome evaluation). As an alternative, the TyG index (using fasting glucose and triglycerides, which are routinely measured) can estimate insulin resistance without requiring a fasting insulin level.

Published HOMA-IR cutoffs (e.g., 2.0, 2.5) were derived from specific study populations and may not apply directly to your patient's ethnic background, age group, or laboratory assay. In the absence of validated local reference ranges, use HOMA-IR as a relative measure — track trends over time within the same individual and within the same lab. A decreasing HOMA-IR in response to intervention is meaningful regardless of the absolute cutoff.

Evidence-Based Methodology

HOMA-IR was developed by Matthews et al. (Diabetologia 1985). The original formula uses mmol/L; the mg/dL adaptation divides by 405. Validation studies suggest HOMA-IR correlates well with gold-standard euglycemic hyperinsulinemic clamp (r=0.88). Reference ranges vary by population; most Western studies use >2.0-2.5 as a threshold for insulin resistance.

Clinical Content Trust

Last reviewed:: April 21, 2026
Guideline version:: General evidence framework v2026.04
Source set version:: Primary-source set v1

How to Interpret Your Result

Higher HOMA-IR values generally reflect greater insulin resistance and lower metabolic insulin sensitivity.

When to Use This Tool

Use this tool in metabolic risk assessment, prediabetes evaluation, and endocrine follow-up where fasting insulin is available.

Limitations

HOMA-IR depends on fasting conditions and assay variability. Thresholds differ across populations and labs, so results should be interpreted within local reference context.

Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.

Changelog

April 21, 2026 · trust-baseline
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Frequently Asked Questions

Most Western population studies define optimal insulin sensitivity as HOMA-IR below 1.0, normal range as 1.0–2.9, and insulin resistance as 2.0 or above (with some studies using 2.5 or higher as the threshold). Values above 2.9 typically indicate significant insulin resistance. These cutoffs are population-specific and assay-dependent; South Asian individuals may have significant insulin resistance at lower values.

HOMA-IR measures insulin resistance at the current moment using fasting glucose and insulin. HbA1c reflects average blood glucose over the past 2–3 months. They provide complementary information: HOMA-IR can be elevated when HbA1c is still completely normal (early insulin resistance with compensated hyperinsulinemia), whereas HbA1c rises only after glucose control begins to deteriorate. HOMA-IR is a metabolic risk marker; HbA1c is a glycemic control marker.

In polycystic ovary syndrome (PCOS), insulin resistance is a central pathophysiological mechanism, present in 50–70% of women with PCOS regardless of BMI. HOMA-IR above 2.5 is commonly used as a threshold in PCOS research and clinical practice. Elevated HOMA-IR in PCOS supports consideration of metformin therapy (which improves insulin sensitivity), dietary modification, and weight management to reduce androgen levels and improve ovulatory function.

Evidence-based strategies to reduce HOMA-IR include: (1) weight loss of 5–7% body weight (reduces HOMA-IR by 20–40%); (2) regular aerobic exercise (150+ min/week moderate intensity); (3) resistance training (improves skeletal muscle insulin sensitivity); (4) dietary changes (reduced refined carbohydrates and ultra-processed foods, higher fiber intake, Mediterranean-style diet); (5) adequate sleep (sleep deprivation acutely elevates insulin resistance); (6) medications such as metformin, GLP-1 receptor agonists, or pioglitazone in appropriate clinical settings.

Online Medical Tools — HOMA-IR

HOMA-IR

How It Works

Obtain fasting labs

Enter fasting glucose and fasting insulin

Interpret your HOMA-IR result

Who Uses the HOMA-IR

Metabolic Syndrome Evaluation

PCOS Screening and Monitoring

Prediabetes Risk Assessment

NAFLD/MASLD Staging

Monitoring Lifestyle Intervention Response

Pro Tips

Must be truly fasting — 8–12 hours, no food or caloric beverages

Insulin assay variability makes absolute cutoffs less reliable

South Asian populations may have insulin resistance at lower HOMA-IR values

PCOS often shows HOMA-IR above 2.5

Pair HOMA-IR with TyG index and lipid ratios for a fuller metabolic picture

5–7% weight loss often reduces HOMA-IR by 20–40%

HOMA-IR does not diagnose diabetes — it estimates insulin resistance

Insulin resistance can be present with a completely normal fasting glucose

Exercise improves HOMA-IR independent of weight loss

Common Questions About Your Results

Evidence-Based Methodology

Clinical Content Trust

How to Interpret Your Result

When to Use This Tool

Limitations

Changelog

Related Tools

HbA1c Converter

Insulin Correction

BMI Calculator

Further Reading

Diabetes Management Guide: Type 1, Type 2, DKA, and HbA1c Monitoring

Frequently Asked Questions