Insulin Resistance

How to Know If You Have Insulin Resistance (Tests & Symptoms)

Insulin resistance is one of the most common hidden drivers behind weight gain, cravings, tiredness, blood sugar problems, and low energy. The difficult part is that many people can have insulin resistance for years while their standard blood sugar tests still appear “normal”.

Many people search for an insulin resistance test, but the reality is that early insulin resistance is often missed. Understanding the symptoms and knowing which tests to ask for can help you identify it much earlier and take action before it progresses.

This page brings together our most useful guides on insulin resistance, including symptoms, testing, blood sugar warning signs, and practical steps you can take to start improving your metabolic health.

If you’re new to this topic, start with our complete guide to insulin resistance to understand how it develops and why it matters.

How do you know if you have insulin resistance?

You may be insulin resistant if you often experience energy crashes, sugar cravings, stubborn belly fat, brain fog, tiredness after meals, or difficulty losing weight despite trying to eat less. These signs do not confirm insulin resistance on their own, but they can be warning signals that your body is struggling to manage blood sugar and insulin effectively.

Common signs of insulin resistance

  • Feeling tired even after a full night’s sleep
  • Craving sugar, bread, pasta, or snacks between meals
  • Weight gain around the stomach
  • Feeling sleepy or sluggish after eating
  • Brain fog or poor concentration
  • Frequent hunger, even after eating
  • Difficulty losing weight
  • Skin tags or darker patches of skin, especially around the neck or underarms

What tests can help detect insulin resistance?

There is no single perfect test used everywhere, but several blood tests can give useful clues. Many people only have fasting glucose or HbA1c checked, but these can sometimes look normal in the early stages because insulin may be working harder to keep blood sugar under control.

Useful tests to discuss with your GP or healthcare professional

If you’re wondering how to test for insulin resistance, these are the most useful options to discuss with your GP. Not all are routinely offered, so it’s important to know what to ask for.

  • Fasting insulin: helps show how much insulin your body is producing while fasting.
  • Fasting glucose: shows your blood sugar level after not eating, but may miss early insulin resistance.
  • HbA1c: gives an average blood sugar picture over roughly 2–3 months.
  • HOMA-IR: a calculation using fasting insulin and fasting glucose to estimate insulin resistance.
  • Oral glucose tolerance test: checks how your body responds after drinking a glucose solution.

Why is insulin resistance often missed?

Insulin resistance can begin before blood sugar rises into the prediabetic or diabetic range. This means someone may be told their blood sugar is “normal” while their body is already producing higher levels of insulin to keep it there.

That is why looking at symptoms, lifestyle, waist size, family history, and the right blood markers can give a fuller picture.

What should you do next?

If you suspect insulin resistance, do not panic. The good news is that insulin resistance can often improve with consistent lifestyle changes, especially around food choices, meal timing, movement, sleep, and reducing constant blood sugar spikes.

Start by learning the basics, understanding your symptoms, and speaking with a qualified healthcare professional if you want testing or medical advice.

Important: This information is for education only and is not a diagnosis. Always speak to your GP or a qualified healthcare professional before making medical decisions or changing medication.

Explore insulin resistance guides

Below you’ll find our latest articles and guides on insulin resistance, blood sugar, testing, symptoms, and practical steps to support better metabolic health.

Frequently asked questions

What is the best test for insulin resistance?

Fasting insulin is one of the most useful early indicators, especially when combined with fasting glucose to calculate HOMA-IR.

Can you have insulin resistance with normal blood sugar?

Yes. Many people have normal glucose levels because their body produces more insulin to compensate.

How do I ask my GP to test for insulin resistance?

You can ask for fasting insulin, fasting glucose, and HbA1c. Not all tests are routinely offered, so it may require discussion.

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