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
Common questions
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.
It's one of the markers used to build a fuller picture of your health. On its own it tells you very little, so it's most informative when reviewed alongside related markers.
It's measured from a standard blood draw at Quest or LabCorp. Leptin is one of the markers included in the OPTML Apex Panel, where your results are read across systems and reviewed by a U.S.-licensed physician.
Reference ranges vary by laboratory, and a single value rarely tells the whole story. Review your result with a physician in the context of your other markers, symptoms, and history.
Leptin is one signal among many. Answer a few quick questions and we’ll point you to the panel that fits.
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.
Find the right 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.
OPTML offers compounded semaglutide and tirzepatide, prescribed and overseen by U.S.-licensed physicians. Compounded drug products are not approved or evaluated for safety, effectiveness, or quality by the FDA. OPTML is not associated with, endorsed by, or affiliated with the manufacturers of FDA-approved branded weight-loss medications, and does not sell or supply those branded products. Anyone interested in an FDA-approved branded medication should consult a licensed healthcare provider or pharmacist. Individual results vary; no specific result is promised, and weight management requires ongoing medical guidance.
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