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Leptin

Published: July 27, 2026Updated: August 25, 2026

Leptin is a hormone produced by adipose tissue that regulates energy balance by inhibiting hunger and regulating metabolism.

Quick summary

Leptin measures the hormone that regulates hunger and metabolism.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
ng/mL
Clinical utility
diagnostic
Result kind
quantitative
FDA-cleared
FDA Cleared Metabolic Assay
interpretation: {"text":"Levels below 3 ng/mL may indicate malnutrition, eating disorders, or hormonal imbalances.","label":"Low Leptin"}; {"text":"Levels above 25 ng/mL may suggest obesity, insulin resistance, or metabolic syndrome.","label":"High Leptin"}

Leptin is a hormone primarily produced by adipose tissue (fat cells) and plays a crucial role in regulating energy balance in the body. It acts on the hypothalamus to inhibit hunger and increase energy expenditure.

The normal reference range for leptin levels in the blood is typically between 3–25 ng/mL. Deviations from this range can indicate metabolic disorders such as obesity or anorexia.

Measuring leptin levels can help diagnose conditions related to energy imbalance, such as obesity, metabolic syndrome, and certain eating disorders. It is also useful in monitoring the effectiveness of weight loss interventions.

Frequently asked questions

What is the role of leptin in the body?
Leptin regulates energy balance by signaling the brain to reduce appetite and increase energy expenditure when fat stores are high.
How is a leptin test performed?
A leptin test involves a simple blood draw, usually taken after an overnight fast, to measure the concentration of leptin in the blood.
  1. 1
    Leptin: The Obesity HormoneSource
  2. 2
    Leptin and ObesitySource

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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy