Insulin Resistance Test

Measures fasting insulin alongside glucose to calculate HOMA-IR — the homeostatic model assessment that quantifies insulin resistance. This is the earliest detectable stage of metabolic dysfunction, appearing years before blood sugar rises enough to trigger a diabetes diagnosis. Standard GP panels rarely include fasting insulin, leaving insulin resistance invisible until it has progressed to pre-diabetes or type 2 diabetes.

Insulin resistance is the metabolic dysfunction that underlies type 2 diabetes, cardiovascular disease, PCOS, fatty liver, and accelerated ageing. It occurs when cells become less responsive to insulin's signal, forcing the pancreas to produce more insulin to maintain normal blood sugar. During this compensatory phase — which can last a decade — fasting glucose remains normal while fasting insulin climbs. The HOMA-IR calculation (fasting insulin × fasting glucose / 22.5) reveals this hidden dysfunction. A HOMA-IR above 2.0 suggests insulin resistance; above 2.5 indicates significant resistance. Standard GP panels test only fasting glucose or HbA1c, both of which remain normal during early insulin resistance — the stage when lifestyle intervention is most effective. This test is particularly valuable for individuals with abdominal weight gain, family history of diabetes, PCOS, or fatty liver — all conditions driven by or associated with insulin resistance. It also serves as a powerful longevity biomarker, as lower insulin levels are consistently associated with healthier ageing across population studies. Fasting for 8-12 hours is required for accurate insulin measurement.