Short answer: Insulin resistance is common in people with PCOS—now called PMOS—and it can occur at any body size. But symptoms, weight, a fasting-insulin value, or an online HOMA-IR calculator cannot diagnose it by themselves. The 2023 International Evidence-Based Guideline recommends assessing glycemic status at diagnosis and identifies a 75-gram oral glucose tolerance test (OGTT) as the most accurate available test for that purpose, regardless of BMI.¹

In 2026, a multistep international consensus process selected polyendocrine metabolic ovarian syndrome (PMOS) as the new name for PCOS, and a transition period is underway.¹⁰ Because the 2023 guideline and most published studies still use “PCOS,” this article uses both terms. You can read why PCOS was renamed PMOS in our full guide.

What is insulin resistance?

Insulin is a hormone made by the pancreas. One of its main jobs is to help move glucose from the bloodstream into cells for energy and to regulate how the liver stores and releases glucose.

Insulin resistance means that tissues such as skeletal muscle, liver, and fat respond less effectively to insulin. The pancreas may compensate by releasing more insulin. During this compensated stage, fasting glucose and A1C can still look normal even though the body needs more insulin to maintain those levels.^{2, 3}

Prediabetes describes glucose values that have risen above the normal range but have not reached the diagnostic range for diabetes. Insulin resistance can contribute to prediabetes, but the terms are not interchangeable.

Why are PCOS/PMOS and insulin resistance linked?

PMOS is a complex endocrine and metabolic condition. Insulin resistance is one important part of its biology, but it is not the only cause and does not explain every person’s symptoms.

When insulin sensitivity falls, the pancreas may produce more insulin to keep glucose stable. Higher insulin levels can interact with ovarian and adrenal hormone pathways, increase androgen production, and reduce sex hormone-binding globulin, which may increase the amount of biologically available androgen. Androgen excess, abdominal adiposity, genetics, sleep disruption, and other factors may then reinforce metabolic dysfunction. The relationship is better understood as an interacting cycle than as a single one-way cause.³

A systematic review and meta-analysis of 28 euglycemic-hyperinsulinemic clamp studies involving 1,965 participants found that insulin sensitivity was 27% lower in the PCOS groups on average, independent of BMI; higher BMI further reduced insulin sensitivity. However, this is a group-level average. It should not be interpreted to mean that every person with PCOS/PMOS has the same degree of insulin resistance.²

Can you have insulin resistance with “lean PCOS”?

Yes. Insulin resistance and abnormal glucose tolerance can occur across body sizes. Higher weight—particularly greater abdominal adiposity—can increase metabolic risk, but a lower BMI does not eliminate that risk. This is why the international guideline recommends glycemic assessment at diagnosis regardless of BMI.^{1, 2}

It is equally important not to assume that a person has insulin resistance simply because of body size. Individual assessment is more accurate than appearance-based assumptions, and care should avoid weight stigma.

What are possible signs of insulin resistance?

Insulin resistance often causes no obvious symptoms, and direct insulin-resistance testing is used primarily in research.⁹ Some clinical findings may raise concern for insulin resistance or broader metabolic risk, including:

• Acanthosis nigricans: darker, thicker, velvety skin, often around the neck, armpits, or groin
• Increasing waist circumference or central weight gain
• Elevated triglycerides, low HDL cholesterol, high blood pressure, prediabetes, or a history of gestational diabetes
• A strong family history of type 2 diabetes

Acanthosis nigricans is associated with insulin resistance, but it can have other causes and deserves clinical evaluation.³

Symptoms that are commonly blamed on insulin resistance—but are nonspecific

• Fatigue or feeling sleepy after eating
• Carbohydrate or sugar cravings
• Difficulty losing weight
• Acne, excess facial hair, or scalp hair thinning
• Irregular or absent menstrual periods

These experiences are real, but they do not prove insulin resistance. They can also be related to sleep apnea, iron deficiency, thyroid disease, medications, depression, insufficient sleep, calorie restriction, androgen excess, or other conditions. Symptoms should guide a conversation with a healthcare professional—not a self-diagnosis.

How is insulin resistance tested in PCOS/PMOS?

There is no single, standardized routine blood test that directly answers, “Do I have insulin resistance?” Direct testing is primarily used in research.⁹ Instead, clinicians usually assess the outcomes that matter most for health: glucose tolerance, diabetes risk, cholesterol, blood pressure, and other individual risk factors.

On a phone or narrow screen, swipe horizontally to view the full table.

The 2023 guideline recommends the 75-gram OGTT as the most accurate test for glycemic status in PCOS/PMOS. If an OGTT cannot be performed, fasting plasma glucose and/or A1C may be considered, with the understanding that their accuracy is lower. The same guideline states that routinely available insulin assays have limited clinical relevance and should not be used routinely.¹

Can you have a normal A1C and still have a problem?

Yes. A normal A1C does not directly measure insulin sensitivity, and it does not always exclude abnormal glucose handling after a glucose challenge.

A 2024 diagnostic-accuracy meta-analysis included nine studies and 2,628 women with PCOS. Compared with the OGTT, an A1C of 6.5% or higher had a pooled sensitivity of 50% for type 2 diabetes, while fasting glucose of 126 mg/dL or higher had a pooled sensitivity of 58%. In other words, at those diagnostic cutoffs, both tests missed a meaningful proportion of OGTT-defined diabetes cases in the included studies.⁴

This does not mean that everyone with a normal A1C needs repeated testing immediately. It means that test selection should reflect PCOS/PMOS status, pregnancy plans, symptoms, prior results, family history, medications, and other individual risk factors.

What do common glucose-test results mean?

The following are general American Diabetes Association criteria for nonpregnant adults. In the absence of unequivocal hyperglycemia, diagnosis requires confirmatory testing; this may repeat the same test or use a different diagnostic test. A random plasma glucose of 200 mg/dL or higher together with classic symptoms or hyperglycemic crisis is another diagnostic route. Pregnancy uses different criteria.⁵

On a phone or narrow screen, swipe horizontally to view the full table.

These ranges classify glycemic status; they do not provide a direct yes-or-no diagnosis of insulin resistance.

When should glucose, cholesterol, and blood pressure be checked?

The international guideline recommends:

• Glycemic assessment at diagnosis for adults and adolescents with PCOS/PMOS
• Repeat glycemic assessment every one to three years, depending on individual diabetes risk factors
• A lipid profile at diagnosis, regardless of age or BMI, with follow-up frequency based on results and overall cardiovascular risk
• Blood-pressure measurement annually and when planning pregnancy or seeking fertility treatment
• For women with PCOS/PMOS who do not already have diabetes, a 75-g OGTT when planning pregnancy or seeking fertility treatment; if it was not completed before conception, it may be offered at the first prenatal visit, and testing should also be offered at 24–28 weeks¹

Your clinician may recommend a different schedule based on prior gestational diabetes, family history, medications, age, weight changes, ethnicity, or previous abnormal results.

What actually helps metabolic health in PCOS/PMOS?

1. Sustainable lifestyle support

The international guideline recommends lifestyle intervention for all women with PCOS/PMOS to support metabolic health. Benefits can occur even without weight loss. Importantly, there is no evidence that one specific diet composition is superior for all anthropometric, metabolic, hormonal, reproductive, or psychological outcomes.¹

A Cochrane review of 15 randomized studies with 498 participants found that lifestyle intervention may modestly improve weight, BMI, and free androgen index, but evidence for glucose-tolerance effects was uncertain and most studies were low quality.⁸ The practical goal is therefore a realistic pattern that can be maintained—not a promise that one restrictive “PCOS diet” will work for everyone.

Depending on individual needs, a sustainable pattern may emphasize vegetables, fruit, legumes, whole grains or other minimally processed carbohydrate sources, adequate protein, unsaturated fats, and fewer sugar-sweetened drinks and highly refined foods. Culture, food access, medical needs, preferences, and any history of disordered eating should shape the plan.

2. Regular movement, including strength training

General guideline targets for adults with PCOS/PMOS include 150–300 minutes of moderate-intensity activity per week or 75–150 minutes of vigorous activity, plus muscle-strengthening activity on two nonconsecutive days. Any increase in movement can be beneficial, and the plan should be individualized.¹

A systematic review and meta-analysis found that vigorous aerobic exercise and resistance training produced moderate reductions in the research marker HOMA-IR compared with control conditions. However, the analysis included only 307 women across 11 studies, and HOMA-IR itself has important limitations.⁶ This supports regular exercise, but it does not prove that everyone needs high-intensity exercise.

3. Clinician-guided medication when appropriate

Metformin may be considered for selected metabolic indications in adults with PCOS/PMOS. The international guideline gives a stronger recommendation in adults with a BMI of 25 kg/m² or higher and notes more limited evidence below that threshold. The decision should account for glucose results, other risk factors, gastrointestinal side effects, pregnancy plans, vitamin B12 risk, and patient preferences.¹

Prescription treatment should not be started, stopped, or replaced based on an online article or supplement claim.

4. Inositol as an optional nutrition-support discussion

Inositol has been studied because of its role in insulin signaling. The systematic review used to inform the 2023 guideline included 30 trials with 2,230 participants; 19 trials could be pooled. The authors concluded that the evidence for PCOS management remains limited and inconclusive, although some metabolic measures may improve and myo-inositol may cause fewer gastrointestinal adverse effects than metformin.⁷

The guideline states that inositol may be considered according to individual preferences and values, while also noting limited clinical benefit and insufficient evidence to recommend a specific type, dose, combination, or ratio.¹

5. Do not overlook sleep

Obstructive sleep apnea is more common in women with PCOS/PMOS even after accounting for BMI. Snoring together with waking unrefreshed, daytime sleepiness, or fatigue should prompt a conversation about validated screening or a sleep evaluation.¹

A note about WrenLife Hormone Health

Metabolic and hormone health are best supported through a comprehensive plan that can include appropriate testing, balanced nutrition, movement, sleep, mental-health support, and clinician-guided treatment when needed.

WrenLife Hormone Health contains myo-inositol and D-chiro-inositol in a 40:1 ratio, whey protein isolate (90% alpha-lactalbumin; contains milk), vitamin D3, vitamin K2, magnesium, chromium, and zinc. It is designed to complement a general wellness routine.*

Research on individual ingredients should not be interpreted as proof of a finished-product clinical effect. The 40:1 ratio is a feature of the WrenLife formulation; current international guidance does not endorse a specific inositol type, dose, combination, or ratio for PCOS/PMOS.¹

Safety: Hormone Health is not a test or treatment for insulin resistance, prediabetes, diabetes, or PCOS/PMOS. It is not intended for use during pregnancy or while breastfeeding. Review the current Supplement Facts and allergen statement. Do not use if you have a milk-protein allergy or known hypersensitivity to any ingredient. If you have a medical condition or take any medication, consult a healthcare professional before use. Because the formula contains vitamin K2, this is especially important if you take warfarin or a similar vitamin-K antagonist.¹¹

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Questions to ask your healthcare professional

• Should I have a 75-gram OGTT even if my fasting glucose or A1C is normal?
• How often should my glycemic status be reassessed based on my individual risk?
• Have my lipid profile and blood pressure been checked?
• Could fatigue or post-meal sleepiness have another cause, such as sleep apnea, anemia, thyroid disease, or a medication effect?
• Would metformin or another clinician-guided option be appropriate for my metabolic results and goals?
• Could a supplement interact with my prescriptions or affect monitoring?

Frequently asked questions

Does everyone with PCOS/PMOS have insulin resistance?

No. Insulin resistance is common and average insulin sensitivity is lower in PCOS populations, but it varies by individual and is not part of the required diagnostic criteria. A group-level research estimate cannot diagnose one person.^{1, 2}

Can I have insulin resistance if my A1C is normal?

Yes. A1C reflects average glucose; it does not directly measure insulin sensitivity. It may also miss abnormal two-hour glucose results that an OGTT detects. The international guideline considers A1C a less accurate alternative when an OGTT cannot be performed.^{1, 4}

What is the best test for insulin resistance in PCOS?

There is no single standardized routine test that directly diagnoses insulin resistance. For clinically important glycemic status, the international guideline recommends a 75-gram OGTT as the most accurate test in PCOS/PMOS, regardless of BMI. Research-grade insulin-clamp testing is not practical for routine care.^{1, 2}

Should I ask for fasting insulin or calculate HOMA-IR?

Not for routine self-diagnosis. The 2023 international guideline states that clinically available insulin assays have limited clinical relevance and are not recommended in routine care.¹

Do I need a low-carbohydrate diet?

Not necessarily. Current evidence does not establish one diet composition as best for everyone with PCOS/PMOS. A sustainable, nutritionally adequate eating pattern tailored to your health needs, preferences, culture, and relationship with food is more consistent with the guideline.¹

Can insulin resistance be reversed?

Insulin sensitivity and glycemic measures can improve with lifestyle changes and, when appropriate, clinician-guided medication. “Reversal” is not a standardized guarantee and should not imply that future risk disappears. Ongoing healthy habits and periodic monitoring remain important.^{1, 9}

Does inositol improve insulin resistance in PCOS/PMOS?

Some trials report improvement in selected metabolic measures, but the overall evidence is limited and inconclusive. The international guideline allows inositol to be considered based on individual preferences and values but does not recommend a specific form, dose, combination, or ratio.^{1, 7}

Scientific references

1. Teede HJ, Tay CT, Laven JJE, et al. Recommendations From the 2023 International Evidence-Based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. Journal of Clinical Endocrinology & Metabolism. 2023;108(10):2447–2469. doi:10.1210/clinem/dgad463.
2. Cassar S, Misso ML, Hopkins WG, Shaw CS, Teede HJ, Stepto NK. Insulin resistance in polycystic ovary syndrome: a systematic review and meta-analysis of euglycaemic-hyperinsulinaemic clamp studies. Human Reproduction. 2016;31(11):2619–2631. doi:10.1093/humrep/dew243.
3. Stener-Victorin E, Teede H, Norman RJ, et al. Polycystic ovary syndrome. Nature Reviews Disease Primers. 2024;10:27. doi:10.1038/s41572-024-00511-3.
4. Belsti Y, Enticott J, Azumah R, et al. Diagnostic accuracy of oral glucose tolerance tests, fasting plasma glucose and haemoglobin A1c for type 2 diabetes in women with polycystic ovary syndrome: A systematic review and meta-analysis. Diabetes & Metabolic Syndrome: Clinical Research & Reviews. 2024;18(3):102970. doi:10.1016/j.dsx.2024.102970.
5. American Diabetes Association Professional Practice Committee for Diabetes. 2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl. 1):S27–S49. doi:10.2337/dc26-S002.
6. Patten RK, Boyle RA, Moholdt T, et al. Exercise Interventions in Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis. Frontiers in Physiology. 2020;11:606. doi:10.3389/fphys.2020.00606.
7. Fitz V, Graca S, Mahalingaiah S, et al. Inositol for Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis to Inform the 2023 Update of the International Evidence-based PCOS Guidelines. Journal of Clinical Endocrinology & Metabolism. 2024;109(6):1630–1655. doi:10.1210/clinem/dgad762.
8. Lim SS, Hutchison SK, Van Ryswyk E, Norman RJ, Teede HJ, Moran LJ. Lifestyle changes in women with polycystic ovary syndrome. Cochrane Database of Systematic Reviews. 2019;(3):CD007506. doi:10.1002/14651858.CD007506.pub4.
9. National Institute of Diabetes and Digestive and Kidney Diseases. Insulin Resistance & Prediabetes. Last reviewed March 2025.
10. Teede HJ, Bahri Khomami M, Morman R, et al. Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome: a multistep global consensus process. The Lancet. 2026;407(10545):2329–2339. doi:10.1016/S0140-6736(26)00717-8.
11. National Institutes of Health Office of Dietary Supplements. Vitamin K: Fact Sheet for Health Professionals. Updated March 29, 2021.

Disclosure: WrenLife sells a dietary supplement containing inositol. This article is educational, distinguishes established guidance from uncertain evidence, and is not a substitute for individualized medical advice.

Explore more evidence-based hormone and metabolic health articles from WrenLife.