The hormone secreted by fat cells that signals energy balance to the brain.
What is it
Leptin is produced primarily by fat cells and acts on the brain to regulate appetite and energy expenditure. It is one of the central hormonal signals in body composition research.
Why it's measured
Leptin levels have been studied in relation to obesity, leptin resistance, and metabolic syndrome features in research literature.
Reference range
Standard laboratory reference
Context-dependent ng/mL
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Often reflects higher adipose tissue mass and has been studied in research on leptin resistance.
Lower
May reflect lower fat mass or caloric restriction in research literature.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Not routinely included in standard panels — measured when investigating appetite regulation or body composition.
Related markers
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Explore the Apex Panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.