Insulin Resistance: Signs, Causes, Tests and How to Reverse It

Written by Naurah Gaspard, DNP, FNP-C, FNP-BC · Medically reviewed by Cherlie Joseph, MSN, FNP-BC · Updated November 2026

Insulin resistance happens when your muscles, fat and liver stop responding well to insulin, so your pancreas has to make more to keep blood sugar normal. It usually has no symptoms, though some people notice dark, velvety skin on the neck or armpits or skin tags. Belly fat and inactivity are the biggest drivers, and losing 5% to 7% of body weight plus regular activity can improve it.

What insulin resistance is

Insulin is the hormone that moves sugar (glucose) from your blood into your cells for energy. With insulin resistance, cells in your muscles, fat and liver respond poorly, so less glucose gets in. Your pancreas makes extra insulin to compensate. As long as it keeps up, blood sugar stays normal, which is why insulin resistance can go unnoticed for years.

Over time, the pancreas may not keep pace. Blood sugar then creeps up into the prediabetes range, and eventually type 2 diabetes. According to the CDC, more than 115 million US adults have prediabetes, most without knowing it, and insulin resistance is a key step on that path.

Signs and symptoms

Most people feel nothing. Clues your body may give include:

• Acanthosis nigricans: darker, thick or velvety skin on the back of the neck, armpits, groin or knuckles
• Skin tags in the same areas
• A larger waist: 40 inches or more for men or 35 inches or more for women, even with a "normal" BMI
• Irregular periods, acne or extra facial hair in women, which can point to polycystic ovary syndrome (PCOS), a condition closely tied to insulin resistance
• Lab findings such as high triglycerides, low HDL cholesterol, or fasting glucose or A1c starting to rise

Feeling tired or hungry after meals is common online advice, but it is not specific. Labs and a look at your overall risk tell you far more.

What causes it

Researchers do not fully understand every cause, but the main drivers are well known:

• Extra weight, especially belly (visceral) fat. Fat around the organs releases substances that promote inflammation and blunt insulin's effect.
• Physical inactivity. Active muscles take up glucose and become more sensitive to insulin.
• Genetics and family history. Some groups, including Black, Hispanic/Latino and Asian American adults, have higher risk, and Asian Americans can develop it at a lower body weight.
• Related conditions: PCOS, fatty liver disease, sleep apnea and a history of gestational diabetes.
• Certain medicines, such as long-term steroids and some antipsychotics.
• Short or poor sleep and chronic stress.

Insulin resistance often shows up alongside high blood pressure, high triglycerides and low HDL as part of metabolic syndrome, which raises heart disease risk.

How it is tested

There is no single routine test for insulin resistance. The most accurate methods are complex and used mainly in research. In everyday care, providers look at a combination of results:

Test	What it shows
A1c	Average blood sugar over about 3 months; 5.7% to 6.4% is prediabetes
Fasting glucose	100 to 125 mg/dL is prediabetes
Lipid panel	High triglycerides with low HDL often travel with insulin resistance
Fasting insulin (sometimes with HOMA-IR)	Can suggest insulin resistance, but labs use different ranges and there is no standard cutoff
Liver enzymes (ALT, AST)	May hint at fatty liver, which is linked to insulin resistance

Waist size and blood pressure matter too. A nurse practitioner licensed in your state at OurTopClinic can order these labs at a nearby lab and walk you through the results.

How to improve or reverse insulin resistance

• Lose 5% to 7% of your weight if you carry extra weight. In the Diabetes Prevention Program, this level of weight loss with more activity lowered the risk of type 2 diabetes by 58%.
• Move most days. Aim for about 150 minutes a week of moderate activity plus strength training twice a week. Even a short walk after meals helps your muscles use glucose.
• Eat for steady blood sugar: vegetables, beans, whole grains, lean protein and healthy fats, with fewer sugary drinks and refined carbs.
• Sleep 7 or more hours and ask about sleep apnea if you snore loudly or wake up tired.
• Talk about medicines. Metformin can help some people with prediabetes, and FDA-approved weight loss medicines, including GLP-1 medicines, may be options for adults with obesity. Whether either is right depends on your labs and history. Prices and coverage change, so check manufacturer sites.

Improvements in insulin sensitivity can begin within weeks of regular activity, even before the scale moves much.

Frequently asked questions

Can insulin resistance be reversed?

Often, yes. Weight loss, regular exercise, better sleep and healthier eating can make your body more sensitive to insulin. Some people still need medication, but improvement is very common.

What does insulin resistance skin look like?

The most common skin sign is acanthosis nigricans: darker, thicker, velvety patches on the back of the neck, armpits or groin. Skin tags in the same areas are also common.

Is insulin resistance the same as prediabetes?

Not exactly. Insulin resistance can exist for years while blood sugar is still normal. Prediabetes means blood sugar has already risen above normal, often because insulin resistance has progressed.

Sources

• NIDDK (NIH): Insulin Resistance and Prediabetes
• CDC: National Diabetes Prevention Program
• CDC: Symptoms of Diabetes

Keep reading

• Can you reverse prediabetes?
• PCOS symptoms
• Early signs of type 2 diabetes
• Browse all conditions and treatments A to Z

This article is for general education and is not a substitute for medical advice. Treatment, including any prescription, is decided by a licensed provider after reviewing your health history. OurTopClinic is not for emergencies; if you have a medical emergency, call 911. OurTopClinic serves adults located in Florida, New Mexico, Oregon and Washington. Learn more at ourtopclinic.com.