NATUROPATHIC DOCTOR IN ONTARIO
PCOS and Insulin Resistance
What Your Blood Sugar Has to Do With Your Hormones
PCOS and Insulin Resistance
When most people think about insulin resistance, they think about blood sugar problems, prediabetes, or type 2 diabetes. What many don’t realize is that insulin resistance is also one of the most powerful drivers of PCOS — and that addressing it is often the single most impactful thing you can do for your hormones, your cycle, and your long-term health.
If you have PCOS and haven’t had your insulin levels tested, or if you’ve been told your blood sugar is “fine” based on fasting glucose alone, this post is worth reading carefully.
The Insulin-Androgen Connection
To understand why insulin matters so much in PCOS, it helps to understand what insulin actually does — and what happens when the system stops working properly.
Insulin is a hormone produced by the pancreas in response to rising blood glucose. Its job is to act like a key, unlocking the doors of your cells so glucose can move in and be used for energy. Under normal circumstances, this is a tightly regulated process that keeps blood sugar stable throughout the day.
Insulin resistance develops when cells become less responsive to insulin’s signal — they stop “hearing” the knock at the door. The pancreas responds by producing more insulin to compensate, driving blood insulin levels chronically higher even when blood glucose looks relatively normal. This is why fasting glucose alone can miss insulin resistance in its early stages: glucose may still be controlled, but only because the pancreas is working overtime to keep it there.
Here’s where PCOS enters the picture. The ovaries have insulin receptors, and they are exquisitely sensitive to insulin. When insulin levels are chronically elevated, the ovaries are directly stimulated to produce more testosterone. This excess testosterone then interferes with the maturation and release of eggs — follicles begin to develop but stall before ovulation, accumulating as the small cysts visible on ultrasound. The result is irregular or absent cycles, elevated androgens, and all the symptoms that come with them: acne, hair thinning, excess hair growth, and more.
What makes this particularly significant is that the hormonal disruption and the insulin resistance reinforce each other. Elevated testosterone worsens insulin sensitivity, which drives insulin higher, which drives testosterone higher. Without addressing the underlying insulin picture, this cycle is very difficult to break.
How Do You Know If Insulin Resistance Is Driving Your PCOS?
This is an important question — and the honest answer is that you can’t know for certain without the right testing.
The standard fasting glucose test that most people receive in routine bloodwork is not sufficient to identify insulin resistance, particularly in younger women with PCOS. A normal fasting glucose does not rule it out. The tests that give a more accurate picture include:
Fasting insulin — measuring insulin directly after an overnight fast. Elevated fasting insulin is one of the clearest indicators of insulin resistance, even when glucose appears normal.
Fasting glucose and HbA1c — useful context alongside fasting insulin, but not sufficient on their own.
2-hour glucose tolerance test with insulin levels — the most sensitive test for catching insulin dysregulation. Blood glucose and insulin are measured fasting, then again one and two hours after drinking a glucose solution. This can reveal patterns of insulin resistance that are invisible on fasting labs alone — including reactive hypoglycaemia, where blood sugar drops too low a few hours after eating, a common but underrecognized pattern in PCOS.
HOMA-IR — a calculation derived from fasting glucose and fasting insulin that provides an estimate of insulin resistance. Useful as a tracking tool over time.
At Sequence Wellness, we order fasting insulin routinely for our PCOS patients, and we use the full glucose tolerance test when the picture isn’t clear from fasting labs. It’s also worth noting that insulin resistance can be present at any body weight — this is not a test that only applies to women who are overweight or struggling with weight loss.
Managing Insulin Resistance in PCOS: A Practical Approach
The good news about insulin-resistant PCOS is that insulin sensitivity responds meaningfully to diet, lifestyle, and targeted supplementation. These changes won’t happen overnight, but they are real, measurable, and often transformative for cycle regularity and androgen levels.
Nutrition: The Foundation
How and what you eat has a more direct impact on insulin than almost any other lifestyle factor. The goal isn’t restriction or perfection — it’s building an eating pattern that keeps blood glucose and insulin from spiking and crashing throughout the day.
Prioritize protein at every meal. Protein has minimal impact on blood glucose and slows the absorption of carbohydrates eaten alongside it. Aiming for 25–35g of protein at breakfast — rather than starting the day with toast or cereal — is one of the most impactful single changes many women with PCOS can make.
Include healthy fats. Like protein, dietary fat slows glucose absorption and supports stable energy. This is not a low-fat approach — olive oil, avocado, nuts, seeds, and fatty fish are all encouraged.
Choose carbohydrates thoughtfully. This doesn’t mean eliminating carbohydrates, which is neither necessary nor sustainable for most people. It means favouring fibre-rich, minimally processed sources — vegetables, legumes, whole intact grains — over refined carbohydrates and sugar, and pairing them with protein and fat to blunt their impact on blood glucose.
Don’t skip meals. Irregular eating patterns can worsen blood sugar volatility and stress the adrenal system. Consistent, satisfying meals spaced regularly throughout the day tend to support more stable insulin levels than restrictive eating or long fasting windows, particularly for women.
Watch liquid sugar. Sweetened beverages — including fruit juice, smoothies heavy in fruit, and specialty coffee drinks — cause rapid glucose and insulin spikes with little satiety in return. Swapping these out is often a quick win.
The two dietary patterns with the strongest evidence base for insulin-resistant PCOS are a low-glycaemic index diet and the Mediterranean diet. Both emphasize whole foods, healthy fats, adequate protein, and fibre-rich carbohydrates — and both have been shown to improve insulin sensitivity, reduce androgens, and support more regular ovulation.
Movement: The Underrated Lever
Exercise is one of the most effective insulin-sensitizing interventions available — and it works through a mechanism that’s independent of weight loss. Muscle contraction during exercise allows cells to take up glucose directly, bypassing the need for insulin. This effect lasts for hours after exercise ends and, with regular training, leads to sustained improvements in insulin sensitivity.
Resistance training (weightlifting, bodyweight exercises, resistance bands) is particularly valuable in PCOS because building muscle mass increases the body’s capacity to dispose of glucose efficiently. Two to three sessions per week of moderate-intensity resistance training is a meaningful starting point.
Walking is consistently underestimated. A 10–20 minute walk after meals significantly blunts the post-meal glucose and insulin rise — one of the simplest, most accessible interventions available.
Moderate-intensity cardio — cycling, swimming, dancing, brisk walking — also improves insulin sensitivity and supports cardiovascular health. The key word is “moderate”: extremely high-intensity training without adequate recovery can raise cortisol and worsen HPA axis dysregulation, which is counterproductive if adrenal PCOS is also present.
Sleep
Sleep deprivation is a direct cause of insulin resistance — even a single night of poor sleep measurably impairs insulin sensitivity the following day. Chronically disrupted or insufficient sleep (less than 7–8 hours for most adults) keeps cortisol elevated, drives sugar cravings, and undermines every other effort to improve blood sugar balance.
If sleep is a struggle, it’s worth addressing directly — not treating it as a secondary concern.
Targeted Supplementation
Several nutrients and compounds have meaningful evidence for improving insulin sensitivity in PCOS. These work best as part of a comprehensive dietary and lifestyle approach, not as substitutes for it.
Myo-inositol and D-chiro-inositol are the most well-supported supplements for insulin-resistant PCOS. Inositols act as second messengers in insulin signalling — they help insulin’s message get through to the cell more effectively. Clinical trials have shown improvements in fasting insulin, androgen levels, cycle regularity, and ovulation rates. The ratio of myo-inositol to D-chiro-inositol that’s most often studied is 40:1, which reflects the physiological ratio found in ovarian tissue. Dosing and formulation matter here — this is worth discussing with your naturopath rather than choosing arbitrarily from the supplement aisle.
Berberine is a plant-derived alkaloid found in several traditional medicinal herbs. It activates an enzyme called AMPK — a key regulator of glucose metabolism — and has been shown in clinical trials to reduce fasting insulin, fasting glucose, and HbA1c with an effect size comparable to metformin in some studies. It also has anti-inflammatory and androgen-lowering properties that make it particularly useful in PCOS with overlapping inflammatory features.
Magnesium is frequently depleted in states of insulin resistance — it’s used up at higher rates when glucose metabolism is impaired. Adequate magnesium supports insulin receptor function, blood sugar regulation, sleep quality, and cortisol management. Many women with PCOS are running low.
Vitamin D plays a role in insulin signalling and is commonly deficient in women with PCOS. Low vitamin D has been associated with worsened insulin resistance, increased androgen levels, and poorer cycle regularity. Testing before supplementing allows for appropriate dosing.
Alpha-lipoic acid (ALA) is an antioxidant with insulin-sensitizing properties that may be a useful adjunct, particularly in women with signs of oxidative stress or inflammatory PCOS overlap.
A Note on Metformin
Metformin is a medication commonly prescribed for insulin-resistant PCOS — and in many cases, it’s a reasonable and effective tool. Its mechanism is similar to berberine (AMPK activation), and it has decades of safety data behind it.
Naturopathic and conventional approaches to insulin resistance in PCOS are not at odds. Some women do best with a combination of medication and lifestyle support; others prefer to address insulin resistance through diet, supplements, and movement alone. What matters is that the insulin picture is being addressed — because without it, the hormonal imbalance underlying PCOS is very difficult to resolve.
The Bottom Line
Insulin resistance is the most common driver of PCOS, and it’s frequently missed or undertreated — especially in women who don’t fit the stereotypical picture. Getting the right testing, understanding your individual insulin pattern, and building a comprehensive plan that addresses blood sugar from multiple angles is often the foundation of meaningful, lasting improvement in PCOS symptoms.
At Sequence Wellness, we assess insulin resistance as a routine part of our PCOS workup, and we build treatment plans around what we find — not a generic protocol.
Book a free 10-minute chat to find out if we’re the right fit for you, or explore more of our PCOS resources below.
[→ A Naturopathic Approach to PCOS: Treating the Root Cause]
[→ The Four Types of PCOS — And Why Your Treatment Should Match Yours]
This article is for informational purposes only and does not constitute medical advice. Please consult a licensed healthcare provider for assessment and treatment recommendations specific to your situation. All Sequence Wellness naturopathic doctors are board certified and licensed by the College of Naturopaths of Ontario (CONO).
Dr. Janna Fung, Naturopathic Doctor
Dr. Janna Fung is a licensed naturopathic doctor with a special interest in dermatology and women’s health. She has a passion for evidence based preventative medicine and strives to empower patients with the knowledge to achieve their optimal health. She understands collaborations is the only way to develop realistic sustainable health/wellness results and strives to develop individualized health goals with patients.
