Leptin levels: what's normal, high and low
A hormone produced by fat cells that signals satiety. Levels generally track body fat percentage.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
Leptin is measured with a standard blood draw after an 8–12 hour fast. A typical reference range is 0.500 – 12.5 ng/mL (male, age 18+; more bands below). At TestWell it's $36.99 all-in as Leptin, results in 3–5 business days, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis.
- Units
- ng/mL
- Sample
- Blood draw
- Fasting
- 8–12 hours
- Results
- 3–5 business days
- Price
- $36.99
- Labs
- Quest or Labcorp · BioReference in NY/NJ
Leptin Reference Range
These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.
| Population | Range |
|---|---|
| Male, age 18+ | 0.500 – 12.5 ng/mL |
| Female, age 18+ | 4.70 – 24.0 ng/mL |
Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.
Have a result in hand? analyze it with your AI assistant using these reviewed ranges, or run it through our explainer. Tools: look up another marker's range · convert lab units
What your Leptin result may mean
Often reflects higher body fat or leptin resistance (common in obesity).
What a high Leptin means: causes, symptoms, next steps ↓Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.
What does a high Leptin mean?
Leptin is made by fat cells, so a high level mostly reports how much body fat is present and, when appetite stays high despite it, leptin resistance — the brain no longer responding to the signal. Women run higher than men. Insulin resistance, sleep deprivation, inflammation and some medications (steroids, some antipsychotics) raise it further. Weight loss lowers it.
Common causes of a high Leptin
- Higher body fat mass
- Leptin resistance in obesity and metabolic syndrome
- Insulin resistance, sleep deprivation, chronic inflammation
- Corticosteroids, some antipsychotics
- Pregnancy, kidney failure (reduced clearance)
Ordered from most to least common.
Symptoms that can go with it
- Persistent hunger and difficulty losing weight despite adequate fat stores
- Often none
What clinicians usually check next
- A1c, fasting insulin, lipids, TSH
- Weight loss through diet, activity and sleep lowers leptin and restores sensitivity
- No approved treatment targets leptin resistance directly
Follow-up tests at TestWell: TSH (Thyroid Stimulating Hormone) ($26.99), TSH + Free T4 ($27.99).
Can I take leptin to lose weight?
No. Leptin therapy only works in the rare people who lack the hormone; in common obesity leptin is already high and the brain has stopped responding.
Educational only — not a diagnosis. A single result outside the range is a prompt to look closer with a clinician.
What does a low Leptin mean?
Low leptin reflects low body fat — athletes, lean individuals, people who have lost significant weight, and those with eating disorders — and tells the brain to conserve energy and raise appetite. Very low leptin is one reason periods stop in low-weight women and why weight regain after dieting is common. Congenital leptin deficiency is extremely rare.
Common causes of a low Leptin
- Low body fat, recent significant weight loss, intensive training
- Anorexia nervosa, malnutrition, fasting
- Lipodystrophy (rare)
- Congenital leptin deficiency (very rare)
Ordered from most to least common.
Symptoms that can go with it
- Increased hunger, low energy, feeling cold
- Absent or irregular periods, low libido, low bone density over time
What clinicians usually check next
- Assess energy availability — intake versus training
- FSH, LH, estradiol or testosterone, TSH, vitamin D
- Sports-medicine or eating-disorder specialist review if periods have stopped or weight is very low
Follow-up tests at TestWell: TSH (Thyroid Stimulating Hormone) ($26.99), TSH + Free T4 ($27.99), FSH (Follicle Stimulating Hormone) ($29.99), LH (Luteinizing Hormone) ($36.99), Estradiol (E2) ($35.99).
Why does leptin fall with dieting?
Leptin drops faster than fat mass, which is the body's defense against starvation: hunger rises and metabolism slows. It is one reason maintenance is harder than the diet itself.
Educational only — not a diagnosis. A single result outside the range is a prompt to look closer with a clinician.
How do you get a Leptin test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. Leptin is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| Leptin | This marker only | $36.99 |
| Metabolism & Weight Loss Panel | 8 tests | $119.99 |
| Total Body Panel | 49 tests | $599.99 |
| Men's Total Body Advanced Panel | 65 tests | $999.99 |
| Women's Total Body Advanced Panel | 65 tests | $999.99 |
Quest vs. Labcorp for Leptin: which lab should you pick?
Both are CLIA-certified national labs and the result is clinically equivalent, so pick whichever location is closer. Your report will print that lab's own reference range, which can differ slightly from the table above.
| Lab | Available | Price |
|---|---|---|
| Quest Diagnostics | Yes | $36.99 |
| Labcorp | Yes | $36.99 |
| BioReference (NY & NJ) | Yes | $36.99 |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
Related Hormones biomarkers
Markers commonly tested alongside Leptin.
Frequently asked
What does a high Leptin mean?
Leptin is made by fat cells, so a high level mostly reports how much body fat is present and, when appetite stays high despite it, leptin resistance — the brain no longer responding to the signal. Women run higher than men. Insulin resistance, sleep deprivation, inflammation and some medications (steroids, some antipsychotics) raise it further. Weight loss lowers it.
Can I take leptin to lose weight?
No. Leptin therapy only works in the rare people who lack the hormone; in common obesity leptin is already high and the brain has stopped responding.
What does a low Leptin mean?
Low leptin reflects low body fat — athletes, lean individuals, people who have lost significant weight, and those with eating disorders — and tells the brain to conserve energy and raise appetite. Very low leptin is one reason periods stop in low-weight women and why weight regain after dieting is common. Congenital leptin deficiency is extremely rare.
Why does leptin fall with dieting?
Leptin drops faster than fat mass, which is the body's defense against starvation: hunger rises and metabolism slows. It is one reason maintenance is harder than the diet itself.
Do I need a doctor's order to test my leptin?
No. TestWell's licensed physician network reviews and approves your order — usually within minutes. You can place an order online without an in-person visit or a referral from your own doctor.
How long does it take to get Leptin results?
Most Leptin results are available in 1–3 business days after your specimen arrives at the lab. You'll get an email the moment your results are ready, with everything viewable in your TestWell portal.
How much does a Leptin test cost?
Our Leptin starts at $36.99. That's the all-in price — no copays, no insurance hoops, no surprise bills. HSA and FSA cards are accepted.
Do I need to fast before my Leptin test?
Yes — for the most accurate result, fast for 8–12 hours before your blood draw. Water is fine; coffee, food, and supplements are not. Your prep instructions will be included with your order.
Which lab will process my Leptin test?
Your test will be processed by Quest Diagnostics, Labcorp, or BioReference depending on which is closest to you and which lab carries the test. All three are CLIA-certified and trusted by hospitals nationwide. You'll choose your lab during checkout from 4,000+ locations.
Ready to test your leptin?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $36.99.