Insulin Resistance in PCOS: What It Actually Means (And Why Your Blood Sugar Might Look Fine)

By Amina Hersi MD

Why insulin resistance is often misunderstood

If you’ve spent any time reading about PCOS, you’ve probably come across some version of:

“Insulin resistance means high blood sugar”
or
“If your glucose is normal, you don’t have insulin resistance.”

Both of these miss the point.

The confusion usually comes from treating glucose and insulin as if they’re the same thing, when they’re doing very different jobs.

Add in social media posts suggesting you can diagnose insulin resistance based on how you feel after eating carbs, or that it can be “reversed” in a few weeks with the right supplement, and it becomes very difficult to separate what’s accurate from what isn’t.

The reality is more nuanced. And that nuance matters, particularly when you’re trying to understand your own PCOS.

What insulin actually does in the body

Insulin is a signalling hormone.

It’s often reduced to “the hormone that controls blood sugar”, but that’s an oversimplification.

After you eat, your blood glucose rises. Your pancreas releases insulin in response. Insulin then acts as a signal, telling your cells to take in glucose from the bloodstream so it can be used for energy or stored.

When this system is working well, glucose is cleared efficiently and blood levels return to baseline.

What insulin resistance actually means

Insulin resistance does not mean high blood sugar.

It means your cells are less responsive to insulin, so the body needs to produce more insulin to achieve the same effect.

A simple way to think about it is this:

Normally, a small amount of insulin is enough to move glucose into cells. With insulin resistance, the body has to release more insulin to get the same response.

The system still works, but it’s working harder.

Why blood sugar can look normal

This is the part that often gets missed.

Insulin rises before glucose does.

In the early stages of insulin resistance, your pancreas compensates by producing more insulin. That extra insulin keeps your blood glucose within the normal range.

So your results might look like this:

• fasting glucose within range
• HbA1c within range
• oral glucose tolerance test unremarkable

On paper, everything looks “normal”.

But what those tests don’t show is how much insulin your body needed to produce to keep glucose there.

You’re measuring the outcome, not the effort behind it.

What this has to do with PCOS

Insulin doesn’t just affect glucose. It also interacts with the ovaries.

Higher insulin levels can stimulate the ovaries to produce more androgens. These androgens are associated with symptoms such as acne, excess hair growth and scalp hair thinning.

Insulin can also affect ovulation by disrupting the hormonal signals that regulate the menstrual cycle.

This is why insulin resistance is commonly discussed in PCOS. It is one of the pathways that can influence both androgen levels and ovulatory function.

If you’ve read our blog on PCOS phenotypes, this is most closely associated with Type A presentations, and can overlap with some Type B patterns.

Can you have PCOS without insulin resistance?

Yes.

Insulin resistance is common in PCOS, but it is not universal.

Some people, particularly those with Type C or Type D phenotypes, may have PCOS without clear metabolic features.

This is also where the idea of “lean PCOS” comes in. People with a lower body weight can still have PCOS, and while insulin resistance can occur, it is not always present.

PCOS is a heterogeneous condition so not everyone has the same underlying drivers.

This is important

Understanding the difference between insulin resistance and blood glucose helps avoid two common misconceptions:

• assuming everything is fine because glucose levels are normal
• assuming insulin resistance must be present in everyone with PCOS

Both of these can lead to an incomplete understanding of what’s going on.

Insulin resistance can be present before glucose becomes abnormal. Equally, it is possible to have PCOS without it.

Supporting metabolic health

Whether or not insulin resistance is present, supporting metabolic health is still relevant.

This includes:

• regular physical activity
• adequate sleep
• managing stress
• a dietary pattern that works for you

There is also research looking at nutrients involved in metabolic pathways.

Magnesium, for example, plays a role in insulin receptor function. Vitamin D has been associated with insulin sensitivity in observational studies, although this does not establish causality.

Inositol, particularly myo-inositol and D-chiro-inositol, has been studied in the context of insulin signalling and ovarian function in PCOS populations. These compounds act as second messengers in insulin pathways, and some studies suggest they may support metabolic and reproductive parameters in certain individuals.

Responses are not uniform, and these approaches do not replace broader lifestyle factors. But they are areas that continue to be studied.

The short version

Insulin resistance does not mean high blood sugar.

It means the body is producing more insulin to keep blood sugar normal.

Understanding that distinction changes how you interpret test results, how you think about PCOS, and how you make sense of your own symptoms.