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Women's Health

PCOS & Blood Sugar: What Your Body Is Trying to Tell You

Living with PCOS can feel overwhelming — especially when you're doing everything right and still not seeing results. The truth is, what's happening inside your body may not show up on a standard blood test. Here's how to see the full picture.

1 in 8

women of reproductive age have PCOS — you are far from alone¹

~50%

of women with PCOS have insulin resistance, even those at a healthy weight²

−10%

drop in fasting blood sugar seen with ketone supplementation in a 2025 clinical trial³

01 — Understanding What's Happening

PCOS Isn't Just About Your Ovaries

If you've been told you have PCOS, you were probably given information about your hormones, your cycle, or your ovaries. What often doesn't get explained is that PCOS is just as much a metabolic condition as it is a hormonal one — and understanding that changes everything.

Many women with PCOS have something called insulin resistance. This simply means your body has to work harder than normal to manage blood sugar. When that happens, insulin levels creep up — and high insulin sends a signal to your ovaries to produce more male hormones than they should. Those extra hormones are behind many of the most frustrating PCOS symptoms: the irregular periods, the acne, the hair changes, the weight that won't budge no matter what you try.

The hopeful part? When you start to bring insulin levels down, many of those symptoms begin to ease too.

Something to hold onto

You're not imagining it, and it's not your fault. PCOS is a whole-body condition, and understanding what's driving your symptoms is the first and most important step toward feeling better.

02 — Why Testing Matters

Your Blood Sugar Might Look Fine — and Still Be a Problem

Here's something that surprises a lot of women: a normal blood sugar reading doesn't always mean your insulin is normal. Many women with PCOS have perfectly ordinary fasting glucose levels while their insulin is running much higher than it should be. A standard test won't catch that.

That's why testing both your blood sugar and your ketones together gives you a much clearer picture. When you combine the two into what's called the Glucose Ketone Index (GKI), you can see how efficiently your body is burning fuel — and whether your insulin is finally starting to come down.

When ketone levels rise, it's a sign your body is shifting away from burning sugar and toward burning fat. That shift also means insulin is dropping. And for women with PCOS, lower insulin means less hormonal disruption — and often fewer symptoms.

A 2025 clinical trial found that women with PCOS who raised their ketone levels saw their fasting blood sugar drop by around 10%, and their testosterone levels fall by over 20%.³ Real numbers. Real change.

03 — Making Sense of Your Numbers

What Does Your GKI Score Actually Mean?

Your GKI is simply your blood sugar reading divided by your ketone reading. The lower the number, the more your body is in a fat-burning, lower-insulin state. Think of it as a window into how your metabolism is really doing — something no single number alone can show you.

GKI Range	What It Means	What It Means for PCOS
1–3	Your body is deeply in fat-burning mode	Strong support for lowering insulin and hormones
3–6	Good fat-burning, well-controlled blood sugar	A great sustainable target for most women
6–9	Some fat-burning, room to improve	A solid starting point — keep going
>9	Blood sugar is dominant, little fat-burning happening	Insulin is likely elevated — this is where to focus first

Everyone's body is different. Talk to your doctor or healthcare provider about what target range makes sense for you personally.

04 — How to Get Started

Testing Is Simpler Than You Think

You don't need to overhaul your life to start getting useful information. A quick morning test takes about two minutes and can give you data that genuinely guides your choices — and helps you see that your efforts are actually working.

Test before breakfast, before your first coffeeYour morning fasting reading is the most consistent and meaningful number you can track. A glass of water is perfectly fine beforehand.
Check your blood sugar firstA small finger prick is all it takes. Write down the number your meter shows — you'll use it in a moment.
Check your ketones straight afterSame finger, same moment. Write that number down too.
Calculate your GKIDivide your blood sugar number by your ketone number. That's your GKI. You can find a full guide to understanding what your result means at bestketonetest.com/pages/what-is-gki.
Don't stress about individual readings — look for the trendYour numbers will vary from day to day, and that is completely normal. What you're watching for is a gentle, gradual improvement over weeks — not perfection every single morning.

05 — Small Changes, Real Results

What Can Help Move Your Numbers in the Right Direction

Insulin resistance responds well to lifestyle changes, and even small improvements can make a meaningful difference in how you feel day to day. You don't have to do everything at once.

Eating fewer refined carbs and added sugars — the most direct way to bring blood sugar down and give your ketones a chance to rise
Adding some strength training — your muscles can pull sugar out of the blood without needing insulin, which is enormously helpful
Protecting your sleep — even one bad night raises blood sugar the next morning, so good sleep is genuinely part of the treatment
Finding ways to manage stress — stress hormones raise blood sugar, and for women with PCOS this has an outsized effect on symptoms
Being patient and kind with yourself — these changes take time, progress isn't always linear, and every small step counts

Worth knowing about supplements

A 2025 clinical study raised ketone levels using an oral supplement — not diet alone — and still saw real improvements in blood sugar and hormone levels. If you're exploring ketone supplements, testing your levels before and after is the only reliable way to know whether they're making a difference for you specifically.

Ready to See What Your Body Is Actually Doing?

The BKT Complete Starter Kit includes everything you need to start testing at home — the meter, glucose strips, and ketone strips, so you can calculate your GKI from day one.

Get the Complete Starter Kit →

Sources

Teede HJ et al. "Polycystic Ovary Syndrome: An Updated Overview Foregrounding Impacts of Ethnicities and Geographic Variations." PMC9785838. Prevalence estimated at 8–13% of reproductive-age women.
Dunaif A et al. "The Polycystic Ovary Syndrome: An Update on Metabolic and Hormonal Mechanisms." PMC4392092. Insulin resistance present in up to 50% of women with PCOS, including lean women.
Rittig N et al. "Ketone supplementation acutely lowers androgen and glucose levels in women with PCOS: a randomized clinical trial." European Journal of Endocrinology, 192(6):717–727, May 2025. PubMed 40393075.

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