--- title: Cystatin C Test type: biomarker url: "https://www.test-well.com/biomarkers/cystatin-c" also_known_as: - cystatin c - cystatin-c category: Metabolic Health units: - mg/L order_price_usd: 36.99 order_item: Kidney Function Test (Cystatin C) order_url: "https://www.test-well.com/tests/cystatin-c" reviewed_at: 2026-09-05 --- # Cystatin C > Cystatin C is measured with a standard blood draw; no fasting is needed. A typical reference range is 0.550 – 1.00 mg/L (age 18–49; more bands below). At TestWell it's $36.99 all-in as Kidney Function Test (Cystatin C), results in 2–4 business days, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis. Also known as: cystatin c, cystatin-c. ## Key facts | Fact | Value | | --- | --- | | Units | mg/L | | Sample | Blood draw | | Fasting | Not required | | Results | 2–4 business days | | Price | $36.99 | | Labs | Quest or Labcorp · BioReference in NY/NJ | ## What does Cystatin C measure? A small protein cleared by the kidneys. An alternative kidney-function marker, especially useful when muscle mass is unusual. ## What is the normal range for Cystatin C? | Population | Reference range | | --- | --- | | age 18–49 | 0.550 – 1.00 mg/L | | age 50+ | 0.610 – 1.21 mg/L | 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 Cystatin C mean? Often reflects reduced kidney function. Less affected by diet and muscle mass than creatinine. ## How do you get tested for Cystatin C? | Order | Type | Price | Includes | | --- | --- | --- | --- | | [Kidney Function Test (Cystatin C)](https://www.test-well.com/tests/cystatin-c) | Single test | $36.99 | This marker | | [Kidney Health Panel](https://www.test-well.com/tests/kidney-health-panel) | Panel | $64.99 | 4 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) | Yes | $22.99 | New York and New Jersey orders route here automatically — state rules keep Quest and Labcorp from accepting self-ordered draws. | - [What a high Cystatin C means (causes, symptoms, next steps)](https://www.test-well.com/biomarkers/cystatin-c/high) ## Common questions about Cystatin C ### Do I need a doctor's order to test my cystatin c? 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 Cystatin C results? Most Cystatin C 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 Cystatin C test cost? Our Kidney Function Test (Cystatin C) 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 Cystatin C test? Fasting is not required for the Cystatin C test. You can have your blood drawn any time of day. ### Which lab will process my Cystatin C 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 - [Mayo Clinic Labs](https://www.mayocliniclabs.com/test-catalog/overview/65653) - [Testing.com (AACC) — Cystatin C Test: What It Measures and How It Works](https://www.testing.com/tests/cystatin-c/) ## Related biomarkers - [Glucose](https://www.test-well.com/biomarkers/glucose) - [Creatinine](https://www.test-well.com/biomarkers/creatinine) - [eGFR](https://www.test-well.com/biomarkers/egfr) - [BUN](https://www.test-well.com/biomarkers/bun) - [ALT](https://www.test-well.com/biomarkers/alt) - [AST](https://www.test-well.com/biomarkers/ast) - [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 2026-09-05. Review policy: https://www.test-well.com/reviewers/youmna-distefano-md Canonical page: https://www.test-well.com/biomarkers/cystatin-c 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.