Insulin resistance blood test (HOMA-IR)

Insulin resistance blood test with glucose, fasting insulin, glycated haemoglobin and the HOMA-IR index. It looks at how the body regulates blood sugar before an abnormality becomes obvious in a conventional blood test and, at the same time, checks whether there are signs of prediabetes or diabetes.

No prescription or appointment needed

Results in 1-2 working days

Includes: Glucose · Insulin · HOMA-IR index · Glycated haemoglobin. See what each one measures

What it is for

It is used to look at two related but different questions. On one hand, glucose and glycated haemoglobin can reveal abnormalities compatible with prediabetes or diabetes. On the other, insulin and the HOMA-IR index help assess whether the body has to produce more insulin than expected to maintain that glucose level.

It can add context when there is excess weight, an increased waist circumference, polycystic ovary syndrome (PCOS), a history of gestational diabetes or close relatives with type 2 diabetes. Bear in mind that the result guides the metabolic assessment, but it does not replace a medical diagnosis.

When it is recommended

A borderline glucose or glycated haemoglobin in a previous blood test
A family history of type 2 diabetes
Excess weight or an increased waist circumference
Polycystic ovary syndrome (PCOS) or a history of gestational diabetes
Before starting a weight loss programme, when you want a metabolic reference point

Clinical comment

Insulin resistance can precede a rise in glucose by years. At first, the pancreas compensates by producing more insulin and manages to keep blood sugar within range. Measuring fasting insulin shows that compensation, and HOMA-IR summarises the relationship between the two figures.

It is important to be precise about what it means. HOMA-IR is not a diagnosis of diabetes, and there is no single cut-off point that is valid for all people and laboratories. Diabetes screening guidelines use glucose and glycated haemoglobin, which are also included in this profile. Insulin and HOMA-IR add metabolic context, but they have to be interpreted together with medical history, body composition and the rest of the blood test.

The glucose tolerance test is not included because it answers a later question and requires staying about two hours at the partner centre. It is usually more useful when glucose or glycated haemoglobin has given a borderline result and a more sensitive test is called for.

Dr. Antonio Mas

What is tested

Glucose: Measures blood sugar at the time the sample is taken. It is one of the tests used to screen for prediabetes and diabetes.
Insulin: Shows how much insulin is circulating while fasting. It is interpreted together with glucose to assess how hard the body is working to keep blood sugar within range.
HOMA-IR index (calculated): An estimate of insulin resistance calculated from fasting glucose and insulin. It is not measured directly and has no universal cut-off point.
Glycated haemoglobin (HbA1c): Reflects average glucose over the last two or three months and gives a more stable picture than a single glucose reading.

These tests are used to calculate Índice HOMA-IR. They are not separate tests.

How to prepare

Fast for 8 to 12 hours. You can drink water. Fasting is essential for interpreting glucose, insulin and the HOMA-IR index. Avoid intense exercise and alcohol the day before, because they can temporarily change glucose metabolism.

You can add

Without another needle. It is offered when you order, so you do not have to decide now.

General blood testA general blood test with full blood count, glucose, cholesterol and kidney and liver function: the basic parameters included in any general check-up.+€59.00
General + nutritional blood testEverything in the general blood test (anaemia, kidneys, liver, cholesterol and glucose) plus iron stores, vitamin D, vitamin B12 and folic acid. It is the broadest add-on: it covers the general and the nutritional in one go.+€129.00
Glucose tolerance test (oral glucose load)Shows how the body responds to a glucose load when fasting glucose or glycated haemoglobin leave doubts; it requires staying at the laboratory for two hours.+€49.00
Thyroid functionBrings together TSH and free T4, the two basic tests for assessing how the thyroid is working.+€29.00

Related blood tests

We have other profiles in Heart and diabetes with more or fewer tests:

The most comprehensive is not always the most useful. If you are not sure, the one we recommend to start with is Cardiovascular risk blood test with ApoB and Lp(a).

What it is based on

American Diabetes Association · Standards of Care in Diabetes 2026 · Diabetes Care 49(Supl 1):S27-S49
Diagnosis and Classification of Diabetes
Recommends screening for prediabetes and diabetes from the age of 35, and at any age when there is excess weight with a risk factor, using fasting glucose or glycated haemoglobin, and repeating every three years if the result is normal. These are the two tests in this profile that are backed by a guideline.
Matthews DR, Hosker JP, Rudenski AS, et al. · Diabetologia 28(7):412-419
Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man
This is the paper that describes the HOMA index based on fasting glucose and insulin. It is worth knowing: no diabetes guideline includes insulin or HOMA-IR in its screening or sets a cut-off point, so they are included here on clinical judgement and usual practice, not on a guideline recommendation.

Protocol designed by Dr. Antonio Mas, specialist in Endocrinology and Nutrition, Spanish medical licence no. 080846289, and reviewed in September 2026.

This blood test is a standardised protocol and does not replace a medical consultation. If you have symptoms, a known condition or a complex clinical situation, speak to your doctor.