If you have PMOS (formerly PCOS), your labs probably included testosterone, a lipid panel, and maybe an A1C or fasting glucose. If those came back normal, you may have been told your blood sugar is “fine.”
But in PMOS, blood sugar can look normal for years while your body works overtime to keep it that way. The extra insulin it takes to do that can drive many of the symptoms you’re dealing with. That’s why I think fasting insulin, or HOMA-IR, is one of the most useful tests someone with PMOS can have, and it’s one many doctors don’t think to order.
Insulin resistance is common in PMOS, at any size
A lot of people assume insulin resistance only shows up in larger bodies. A study using the most accurate test available found insulin resistance in 75% of lean women with PCOS and 95% of those in larger bodies. If you’ve been told your insulin is probably fine because of your size, that isn’t a safe assumption.
When your cells don’t respond to insulin well, your pancreas makes more of it to keep blood sugar in range. Your glucose looks normal, but your insulin is running high, and high insulin affects much more than blood sugar.
How high insulin drives PMOS symptoms
More androgens. Insulin acts directly on the ovaries, signaling them to make more testosterone and other androgens. It also lowers SHBG, a protein that normally binds testosterone and keeps it in check. Together, that means more active testosterone circulating in your body, which shows up as irregular periods, acne, unwanted hair growth, and thinning hair on the scalp. When researchers lowered insulin levels in women with PCOS using metformin, free testosterone dropped by about 40%.
Irregular cycles and ovulation. The same hormonal shift can interfere with ovulation, which is one reason cycles become irregular or stop. Lowering insulin often helps cycles become more regular.
Energy crashes and intense hunger. Reactive hypoglycemia is common in PMOS. Studies have found it in about half of lean women with PCOS and up to two-thirds of those in larger bodies, compared with roughly 12% of women without blood sugar issues. After a meal that’s mostly simple carbs, insulin overshoots and blood sugar drops sharply a few hours later. That drop can bring on shakiness, irritability, fatigue, and urgent hunger, and it can trigger cortisol and adrenal androgens, which feed back into PMOS symptoms.
High insulin also affects hunger signals more directly. Insulin normally helps the brain regulate how much you eat, but when insulin stays high, the brain can become less responsive to it. At the same time, fullness hormones like leptin and CCK don’t work as well in PMOS, and ghrelin, the hormone that drives hunger, doesn’t drop as much after meals. Together, that can mean feeling hungry soon after eating, or never feeling quite satisfied. It’s biology, not a lack of willpower.
Fullness that doesn’t last. Research suggests hunger hormones may respond differently in PMOS. In one study, ghrelin, the hormone that signals hunger, dropped less after meals in women with PCOS than in women without it. Many of my clients describe feeling hungry again soon after eating. That’s a physical pattern, not a lack of willpower.
Why glucose and A1C aren’t enough
Fasting glucose and A1C tell you whether your body is keeping blood sugar in range. They don’t tell you how much insulin it takes to do it. Someone can have perfect glucose numbers and very high insulin, and in PMOS, that high insulin is often what’s driving symptoms.
What the tests are
Fasting insulin measures the insulin in your blood after an overnight fast.
HOMA-IR combines your fasting insulin and fasting glucose into one estimate of insulin resistance. It just needs both numbers from the same morning draw. In one study of women with PCOS, a HOMA-IR above 2.0 identified most of those who turned out to have glucose intolerance.
The 2-hour oral glucose tolerance test (OGTT) checks how your body handles a set amount of sugar. If your OGTT measures insulin as well as glucose, even better.
Where I disagree with the guidelines
The 2023 international PCOS guideline doesn’t recommend fasting insulin or HOMA-IR for routine use. Its reasoning is that insulin tests aren’t standardized across labs and there’s no universal cutoff. Those limitations are real.
I respectfully disagree with leaving them out, though. Insulin resistance is at the center of PMOS for most people, and a fasting insulin is inexpensive, needs only one blood draw, and can show a problem years before glucose or A1C change. An imperfect number that points you in the right direction is more useful than no number at all. In my practice, seeing an elevated fasting insulin often helps clients understand why they feel the way they do, and it gives us something to track as habits or medications start working.
How to ask your doctor
You could say: “I know insulin resistance is common with PMOS, even when glucose is normal. Could we check a fasting insulin along with my fasting glucose, so we can calculate HOMA-IR?”
Get it done in the morning after an overnight fast, and ask for your actual numbers, not just “normal.” Labs use different reference ranges, so it helps to look at your results with someone who knows PMOS.
If your insulin comes back high
It doesn’t mean you did anything wrong, and it doesn’t mean you need to cut carbs or diet. Eating regularly, pairing carbs with protein, fat, and fiber, moving in ways you enjoy, sleeping well, and sometimes medication like metformin or a GLP-1 can all bring insulin down, often without any change in weight.
If you’ve had labs done and want help making sense of them, I’d love to talk. You can learn more about how I support people with PMOS.
Related: Making Sense of Your PMOS Labs
Sources
Women with polycystic ovary syndrome have intrinsic insulin resistance on euglycaemic-hyperinsulaemic clamps. Stepto et al., Human Reproduction, 2013.
Insulin Resistance and the Polycystic Ovary Syndrome Revisited: An Update on Mechanisms and Implications. Diamanti-Kandarakis and Dunaif, Endocrine Reviews, 2012.
Decreases in ovarian cytochrome P450c17α activity and serum free testosterone after reduction of insulin secretion in polycystic ovary syndrome. Nestler and Jakubowicz, New England Journal of Medicine, 1996.
Reactive Hypoglycemia: A Trigger for Nutrient-Induced Endocrine and Metabolic Responses in Polycystic Ovary Syndrome. Karakas, Journal of Clinical Medicine, 2023.
Postprandial ghrelin, cholecystokinin, peptide YY, and appetite before and after weight loss in overweight women with and without polycystic ovary syndrome. Moran et al., American Journal of Clinical Nutrition, 2007.
The Usefulness of HOMA-IR for Detection of Glucose Intolerance in Thai Women of Reproductive Age with Polycystic Ovary Syndrome. Wongwananuruk et al., International Journal of Endocrinology, 2012.
International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome 2023. Monash University.
The impact of eating behavior on psychological symptoms typical of reactive hypoglycemia: a pilot study comparing women with polycystic ovary syndrome to controls. Barry et al., Appetite, 2011.
Food Cravings and Obesity in Women with Polycystic Ovary Syndrome: Pathophysiological and Therapeutic Considerations. Stefanaki et al., Nutrients, 2024.
Impaired insulin action in the human brain: causes and metabolic consequences. Heni et al., Nature Reviews Endocrinology, 2015.
