HOMA-IR index explained
- Updated
- 2026-09-30
- Every number with its source
What the HOMA-IR index is and how it is calculated
HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) is a calculated indicator that shows how the body responds to insulin. It is worked out from two tests carried out on the same fasting blood sample — the glucose and insulin concentrations — using a formula (glucose × insulin, divided by a constant). HOMA-IR is not measured separately in the laboratory as a single number; it is calculated from those two primary tests, which is why the result report often shows three lines: glucose, insulin and the calculated HOMA-IR. The indicator is used as an indirect estimate of insulin resistance — a state in which the body's cells respond more weakly to insulin and the pancreas has to produce more of it so that glucose can get into the cells. Insulin resistance often accompanies excess weight, type 2 diabetes, polycystic ovary syndrome (PCOS) and metabolic syndrome. MedlinePlus states that raised insulin together with normal or slightly raised glucose may indicate insulin resistance, and that the insulin test is also used to find the cause of hypoglycaemia and to adjust the treatment of type 2 diabetes.
What appears on your result report
| Line on the report | Where the number comes from |
|---|---|
| Fasting glucose | Measured in the laboratory from the fasting blood sample |
| Fasting insulin | Measured in the laboratory from the same fasting blood sample |
| HOMA-IR | Not measured separately — calculated from those two results (glucose × insulin, divided by a constant) |
When it is tested
When HOMA-IR is tested
- When there is excess weight or obesity, particularly around the abdomen, and the risk of insulin resistance is being assessed
- When prediabetes has been diagnosed, or there are risk factors for type 2 diabetes (family history, gestational diabetes)
- When a woman has been diagnosed with, or is suspected of having, polycystic ovary syndrome (PCOS)
- When there are skin changes typical of insulin resistance (darkened, thickened skin on the neck or in the armpits — acanthosis nigricans)
- When there are cardiovascular risk factors together with increased body weight
- To follow the effect of treatment or lifestyle changes over time, when a doctor has recommended it
How to prepare
- You must not eat or drink (except water) for 8–12 hours before the test — blood is taken in the morning, fasting
- Before the test it is worth discussing with your doctor whether to stop biotin (vitamin B7) supplements, as they can distort the insulin test result
- Tell your doctor before the test about the medicines you take, including those for diabetes
Reference limits
We have not found a single, universally confirmed HOMA-IR reference limit in a reliable source with a specific number — the limit depends on the insulin assay method the laboratory uses and on the population. You will find your own laboratory's exact reference limit on your result report, and a doctor always helps to interpret it.
A raised HOMA-IR
A raised HOMA-IR is considered a sign of insulin resistance — the body's cells respond more weakly to insulin, so the pancreas produces more of it. MedlinePlus states that high insulin together with normal or slightly raised glucose may indicate exactly this state. The most common causes are excess weight, low physical activity, PCOS or developing type 2 diabetes; the final assessment is made by a doctor together with other tests.
Common causes
- Excess weight or obesity, particularly abdominal fat
- Low physical activity and a sedentary lifestyle
- Polycystic ovary syndrome (PCOS)
- Prediabetes or developing type 2 diabetes
- Metabolic syndrome (together with raised blood pressure, raised triglycerides and reduced HDL cholesterol)
Possible signs
- There are often no symptoms — insulin resistance is usually found by a test rather than by how a person feels
- Darkened, thickened skin on the neck, in the armpits or the groin (acanthosis nigricans)
- Increased weight, or difficulty losing it
What to discuss with a doctor
- Fasting glucose, HbA1c and a glucose tolerance test — to assess whether prediabetes or diabetes is already present
- A lipid profile (cholesterol, triglycerides) and blood pressure — to assess signs of metabolic syndrome
- Body weight, waist circumference and physical activity habits, discussed with a doctor
- When to repeat the test, if lifestyle is being changed or treatment is prescribed
HOMA-IR is not a diagnosis
HOMA-IR is informational, not diagnostic — it helps to assess the likelihood of insulin resistance, but a diagnosis is always made by a doctor, after assessing additional tests and overall health. A different picture, low insulin together with raised glucose, may mean that the pancreas cannot make enough insulin (MedlinePlus). For this reason the meaning of a HOMA-IR value is always discussed with a doctor together with the other test results.
Related pages
Full site in Lithuanian: proactiva.app
Frequently asked questions
›What is the HOMA-IR index?
HOMA-IR is a calculated indicator, worked out by a formula from the glucose and insulin taken fasting from the blood. It is used as an indirect estimate of insulin resistance — a state in which the body's cells respond more weakly to insulin (MedlinePlus).
›What is a normal HOMA-IR?
We have not so far found a single, universally confirmed HOMA-IR reference limit in a reliable source with a specific number — the limit depends on the insulin assay method the laboratory uses and on the population. You will find your own laboratory's exact reference limit on your result report; a doctor always helps to interpret it.
›What does a raised HOMA-IR mean?
A raised HOMA-IR is considered a sign of insulin resistance. According to MedlinePlus, high insulin together with normal or slightly raised glucose may indicate that the body's cells respond more weakly to insulin. The most common causes are excess weight, low physical activity, PCOS or developing type 2 diabetes.
›Do I need to fast before a HOMA-IR test?
Yes. You must not eat or drink (except water) for 8–12 hours before the test, because both glucose and insulin have to be measured fasting for the result to be accurate (MedlinePlus).
›How does HOMA-IR differ from a glucose or HbA1c test?
Glucose and HbA1c show the amount of sugar in the blood, while HOMA-IR shows how efficiently the body uses insulin to regulate that sugar. Insulin resistance can appear before glucose or HbA1c rise, so HOMA-IR can help to notice a change earlier.
›Is HOMA-IR a diagnosis?
No. HOMA-IR is informational, not diagnostic — it helps to assess the likelihood of insulin resistance, but a diagnosis is always made by a doctor, after assessing additional tests and overall health.
›How is HOMA-IR calculated?
The most commonly used formula is fasting glucose (mmol/l) × fasting insulin (µU/ml), divided by 22.5 — this is how it is written, for example, in a 2022 study in the Caspian Journal of Internal Medicine. The authors of that study note that the cut-offs they found were lower than in other studies and recommend setting cut-offs separately for each population — which is why there is no single universal norm. The result is informational, not diagnostic.
Sources
Related markers
This site is not an emergency service. If severe chest or head pain, breathlessness, confusion, difficulty speaking, heavy bleeding or another acute problem has come on suddenly — do not wait for tests, call 112.
This information is not a diagnosis and does not replace a consultation with a doctor. Reference ranges depend on the laboratory, your age and sex — always compare your result with the range printed on your own report.