Symptoms and Early Signs of Insulin Resistance

Insulin resistance usually develops silently. Many people have it for years before their blood glucose rises enough to be diagnosed with prediabetes or type 2 diabetes. Still, the body often gives subtle early warning signs that insulin is not working as it should.

This guide explains the most common symptoms and early clues to watch for, and when to speak with a healthcare professional. For a broader overview of what insulin resistance is and why it happens, visit our complete guide to insulin resistance.

In this article

• Why Many People Have No Symptoms
• 1. Fatigue and Low Energy
• 2. Weight Gain Around the Middle
• 3. Skin Changes: Acanthosis Nigricans & Skin Tags
• 4. Increased Hunger and Cravings
• 5. Brain Fog and Difficulty Concentrating
• 6. PCOS and Reproductive Symptoms
• 7. High Blood Pressure, Cholesterol & Metabolic Syndrome

Why Many People Have No Symptoms

In the early stages of insulin resistance, the pancreas compensates by producing more insulin. As long as this “extra insulin” keeps blood glucose in range, there may be no noticeable symptoms. This is why insulin resistance is so common and often missed for years.

But as the condition progresses, several physical and metabolic signs can appear.

1. Fatigue and Low Energy

Many people notice increasing tiredness — especially after meals. When insulin cannot move glucose efficiently into muscle cells, the body struggles to use food for fuel, leading to fluctuating energy and a sense of post-meal exhaustion.

2. Weight Gain Around the Middle

Insulin resistance promotes fat storage, particularly around the abdomen (visceral fat). This creates a cycle, because visceral fat itself worsens insulin resistance. If you’ve gained weight around the middle without major lifestyle changes, this may be a sign worth discussing with your doctor.

3. Skin Changes: Acanthosis Nigricans and Skin Tags

Certain skin features are strongly associated with high insulin levels:

• Acanthosis nigricans – dark, velvety patches usually on the neck, armpits, knuckles or groin.
• Multiple skin tags – often on the neck or underarms.

These changes occur because insulin is a growth-promoting hormone. Persistently elevated insulin levels stimulate the skin to thicken.

4. Increased Hunger and Cravings

When cells are not responding to insulin, glucose remains elevated in the bloodstream instead of entering the cells. The brain interprets this as “not enough fuel,” triggering increased hunger — often for carbohydrate-rich foods.

5. Brain Fog and Difficulty Concentrating

Fluctuating insulin and glucose levels can affect mental clarity. People often describe feeling “foggy,” forgetful or sluggish, especially after carbohydrate-heavy meals.

6. PCOS and Reproductive Symptoms

In women, insulin resistance is a major driver of polycystic ovary syndrome (PCOS). Symptoms may include:

• irregular or absent periods
• acne or oily skin
• excess facial or body hair
• difficulty losing weight

7. High Blood Pressure, Cholesterol and Metabolic Syndrome

Insulin resistance is closely linked with metabolic syndrome. Your doctor may notice changes long before you feel unwell, such as:

• raised blood pressure
• high triglycerides
• low HDL (“good”) cholesterol
• fatty liver on a scan or blood test

Trusted External Sources

• NIDDK – Diabetes & Insulin Resistance
• CDC – Insulin Resistance Basics