Insulin resistance testing

Insulin resistance is genuinely common in PCOS, so it is reasonable to want it measured. The evidence on how to measure it is weaker than the popular framing suggests.

Fasting insulin and HOMA-IR: The 2023 international PCOS guideline concluded that available insulin assays have limited clinical relevance, and it does not recommend fasting insulin or HOMA-IR as routine diagnostic tests. The widely shared “optimal 2–5 mcIU/mL” target is not a guideline threshold. Filia lists insulin but does not calculate HOMA-IR, and does not interpret either against a fertility cutoff. The contrary evidence is real and worth knowing: at least one study found elevated HOMA-IR independently predicted lower IVF pregnancy and live birth rates. That association has not translated into a recommendation to test, because the assays are poorly standardised and the result rarely changes management.

Glucose tolerance testing: Where a formal glycemic assessment is indicated in PCOS, guidelines prefer a 75g oral glucose tolerance test over fasting glucose or HbA1c alone. That test is ordered and supervised by your own clinician — Filia does not offer it. HbA1c is in Filia’s catalog and gives longer-term glycemic context, but it is the less preferred test in PCOS when an OGTT is feasible.

When to raise this with a clinician: PCOS diagnosed or suspected, BMI over 25, family history of diabetes, acanthosis nigricans, or central adiposity. Metabolic health matters to cycles and to pregnancy, but no insulin measurement diagnoses infertility, and none of these tests is a fertility score.