--- title: Leptin Test type: biomarker url: "https://www.test-well.com/biomarkers/leptin" also_known_as: - leptin category: Hormones units: - ng/mL order_price_usd: 36.99 order_item: Leptin order_url: "https://www.test-well.com/tests/leptin" reviewed_at: 2026-09-08 --- # Leptin > 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. Also known as: leptin. ## Key facts | Fact | Value | | --- | --- | | Units | ng/mL | | Sample | Blood draw | | Fasting | 8–12 hours | | Results | 3–5 business days | | Price | $36.99 | | Labs | Quest or Labcorp | ## What does Leptin measure? A hormone produced by fat cells that signals satiety. Levels generally track body fat percentage. ## What is the normal range for Leptin? | Population | Reference range | | --- | --- | | Male, age 18+ | 0.500 – 12.5 ng/mL | | Female, age 18+ | 4.70 – 24.0 ng/mL | Reference intervals differ slightly between labs; the range printed on your report is the one to interpret against. Ranges are usually set so 95% of healthy people fall inside them. ## 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 high Leptin 1. Higher body fat mass 2. Leptin resistance in obesity and metabolic syndrome 3. Insulin resistance, sleep deprivation, chronic inflammation 4. Corticosteroids, some antipsychotics 5. Pregnancy, kidney failure (reduced clearance) ### Symptoms that go with high Leptin - 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)](https://www.test-well.com/tests/tsh) ($26.99), [TSH + Free T4](https://www.test-well.com/tests/tsh-with-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. ## 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 low Leptin 1. Low body fat, recent significant weight loss, intensive training 2. Anorexia nervosa, malnutrition, fasting 3. Lipodystrophy (rare) 4. Congenital leptin deficiency (very rare) ### Symptoms that go with low Leptin - 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)](https://www.test-well.com/tests/tsh) ($26.99), [TSH + Free T4](https://www.test-well.com/tests/tsh-with-free-t4) ($27.99), [FSH (Follicle Stimulating Hormone)](https://www.test-well.com/tests/fsh) ($29.99), [LH (Luteinizing Hormone)](https://www.test-well.com/tests/luteinizing-hormone) ($36.99), [Estradiol (E2)](https://www.test-well.com/tests/estradiol) ($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. ## How do you get tested for Leptin? | Order | Type | Price | Includes | | --- | --- | --- | --- | | [Leptin](https://www.test-well.com/tests/leptin) | Single test | $36.99 | This marker | | [Metabolism & Weight Loss Panel](https://www.test-well.com/tests/metabolism-panel) | Panel | $119.99 | 8 tests | | [Total Body Panel](https://www.test-well.com/tests/total-body-panel) | Panel | $499.99 | 49 tests | ## Quest vs Labcorp vs BioReference | Lab | Available | Price | Notes | | --- | --- | --- | --- | | Quest Diagnostics | Yes | $36.99 | Choose Quest at checkout; walk-in patient service centers in every state TestWell serves outside NY and NJ. | | Labcorp | Yes | $36.99 | Choose Labcorp at checkout; walk-in patient service centers in every state TestWell serves outside NY and NJ. | | BioReference (NY & NJ) | No | — | Not available in NY/NJ for this test. | ## Common questions about Leptin ### 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. ## Sources - [Quest Diagnostics](https://testdirectory.questdiagnostics.com/test/test-detail/36149/leptin) - [Testing.com (AACC) — Leptin Test: What It Measures and How It Works](https://www.testing.com/tests/leptin/) ## Related biomarkers - [Total Testosterone](https://www.test-well.com/biomarkers/total-testosterone) - [Free Testosterone](https://www.test-well.com/biomarkers/free-testosterone) - [SHBG](https://www.test-well.com/biomarkers/shbg) - [Estradiol](https://www.test-well.com/biomarkers/estradiol) - [Cortisol AM](https://www.test-well.com/biomarkers/cortisol-am) - [DHEA-S](https://www.test-well.com/biomarkers/dhea-s) - [Reference range lookup tool](https://www.test-well.com/tools/reference-range-lookup) - [Lab unit converter](https://www.test-well.com/tools/lab-unit-converter) - [All biomarkers](https://www.test-well.com/biomarkers) --- Medically reviewed by Youmna DiStefano, MD (Medical Reviewer, TestWell); last reviewed 2026-09-08. Review policy: https://www.test-well.com/reviewers/youmna-distefano-md Canonical page: https://www.test-well.com/biomarkers/leptin Machine-readable catalog: https://www.test-well.com/api/catalog.json · MCP server: https://www.test-well.com/mcp · Overview for agents: https://www.test-well.com/llms.txt Prices are cash-pay, in USD, and include physician authorization; every order adds one flat $6 lab processing fee. Educational content is not a diagnosis — discuss results with a clinician.