Insulin

MetabolicMetabolism & EnergyBlood

Insulin is a peptide hormone produced by beta cells in the pancreas. It is the master regulator of glucose metabolism — signaling cells to absorb glucose from blood, promoting glycogen storage in the liver, and inhibiting fat breakdown. Insulin also plays roles in protein synthesis, cell growth, and lipid metabolism.

Why it matters: Fasting insulin is the earliest detectable marker of insulin resistance, often elevated years before glucose or HbA1c become abnormal. High insulin drives fat storage, raises triglycerides, lowers HDL, increases inflammation, and promotes cellular aging. It is arguably the most important metabolic marker to track.

Reference Range
2.6 – 24.9mU/L
2.6
24.9LowNormalHigh
Symptoms of Low Insulin
High blood sugar
Unintended weight loss
Excessive thirst
Fatigue
Symptoms of High Insulin
Weight gain (especially abdominal)
Sugar cravings
Fatigue after meals
Skin tags or darkened skin folds
What Moves It

May increase with:

Insulin resistance (compensatory hyperinsulinemia)
High carbohydrate meals
Obesity (especially visceral)
Physical inactivity
Poor sleep
Chronic stress
Excessive fructose intake
Insulinoma (rare)

May decrease with:

Low-carb or ketogenic diet
Intermittent fasting
Regular exercise (especially resistance training)
Weight loss
Adequate sleep
Berberine (similar mechanism to metformin)
Chromium and magnesium
Time-restricted eating
Associated Conditions
Insulin resistanceType 2 diabetesMetabolic syndromePCOSNon-alcoholic fatty liver diseaseCardiovascular disease
Related Markers
GlucoseHOMA-IRHbA1cTriglycerides
Common questions

What is Insulin?

Insulin is a peptide hormone produced by beta cells in the pancreas. It is the master regulator of glucose metabolism — signaling cells to absorb glucose from blood, promoting glycogen storage in the liver, and inhibiting fat breakdown. Insulin also plays roles in protein synthesis, cell growth, and lipid metabolism.

What might a high or low Insulin mean?

Fasting insulin is the earliest detectable marker of insulin resistance, often elevated years before glucose or HbA1c become abnormal. High insulin drives fat storage, raises triglycerides, lowers HDL, increases inflammation, and promotes cellular aging. It is arguably the most important metabolic marker to track.

What is the typical reference range for Insulin?

The general-population reference range shown here is 2.6 – 24.9 mU/L. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.

What can affect Insulin?

It may be higher with: Insulin resistance (compensatory hyperinsulinemia), High carbohydrate meals, Obesity (especially visceral), Physical inactivity, Poor sleep, Chronic stress, Excessive fructose intake, Insulinoma (rare). It may be lower with: Low-carb or ketogenic diet, Intermittent fasting, Regular exercise (especially resistance training), Weight loss, Adequate sleep, Berberine (similar mechanism to metformin), Chromium and magnesium, Time-restricted eating.

More in Metabolic
C-PeptideGlucoseHbA1cHbA1c (IFCC)HOMA-IR

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