eGFR (Cystatin C) levels: what's normal, high and low
Estimated kidney filtration rate calculated from cystatin C. Often used to confirm creatinine-based eGFR.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
eGFR (Cystatin C) is measured with a standard blood draw; no fasting is needed. A typical reference range is 60.0 – 120 mL/min/1.73m2. At TestWell it's $23.99 all-in as Renal Panel, 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.
- Units
- mL/min/1.73m2 / mL/min
- Sample
- Blood draw
- Fasting
- Not required
- Results
- 2–4 business days
- Price
- $23.99
- Labs
- Quest or Labcorp · BioReference in NY/NJ
eGFR (Cystatin C) 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 |
|---|---|
| age 18+ | 60.0 – 120 mL/min/1.73m2 |
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 eGFR (Cystatin C) result may mean
Sustained values below 60 can indicate chronic kidney disease.
What a low eGFR (Cystatin C) 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 low eGFR (Cystatin C) mean?
A low cystatin C–based eGFR means the kidneys are filtering below expected for age. Because cystatin C is not inflated by muscle mass, meat or creatine, it is a more trustworthy kidney signal than creatinine in athletes, older adults and people with low muscle mass — though thyroid disease, steroids and obesity can lower it without kidney change. Below 60 for three months defines chronic kidney disease.
Common causes of a low eGFR (Cystatin C)
- Chronic kidney disease: diabetes, hypertension, glomerular disease, polycystic kidney disease
- Acute kidney injury: dehydration, NSAIDs, contrast, infection
- Hyperthyroidism, high-dose corticosteroids (raise cystatin C, lower this eGFR)
- Obesity, smoking, inflammation (modest)
- Normal aging (eGFR falls ~1 mL/min per year after 40)
Ordered from most to least common.
Symptoms that can go with it
- Usually none until well below 30
- Fatigue, swelling, foamy urine, nocturia, itching as kidney disease progresses
What clinicians usually check next
- Creatinine-based eGFR at the same draw; the combined equation is the most reliable single number
- Urine albumin-to-creatinine ratio
- Blood pressure, A1c, TSH, medication review (NSAIDs, PPIs, lithium)
- Repeat in 3 months to confirm before any CKD label; nephrology referral below 45 or if falling fast
Follow-up tests at TestWell: TSH (Thyroid Stimulating Hormone) ($26.99), TSH + Free T4 ($27.99).
Seek care promptly if
- A sharp fall from a recent value, very little urine, or swelling with breathlessness — same-day care
My creatinine eGFR is normal but the cystatin C eGFR is low — which is right?
Possibly the cystatin C one: creatinine underestimates kidney disease in people with low muscle mass. The reverse mismatch happens in muscular people. When they disagree, clinicians use the combined equation and the urine albumin to decide.
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 eGFR (Cystatin C) test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. eGFR (Cystatin C) is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| Renal Panel | This marker only | $23.99 |
| Kidney Health Panel | 4 tests | $64.99 |
| Total Body Essentials Panel | 39 tests | $399.99 |
| Total Body Panel | 49 tests | $599.99 |
| Men's Total Body Advanced Panel | 65 tests | $999.99 |
Quest vs. Labcorp for eGFR (Cystatin C): 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 | $23.99 |
| Labcorp | Yes | $23.99 |
| BioReference (NY & NJ) | Yes | $24.99 |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
Frequently asked
What does a low eGFR (Cystatin C) mean?
A low cystatin C–based eGFR means the kidneys are filtering below expected for age. Because cystatin C is not inflated by muscle mass, meat or creatine, it is a more trustworthy kidney signal than creatinine in athletes, older adults and people with low muscle mass — though thyroid disease, steroids and obesity can lower it without kidney change. Below 60 for three months defines chronic kidney disease.
My creatinine eGFR is normal but the cystatin C eGFR is low — which is right?
Possibly the cystatin C one: creatinine underestimates kidney disease in people with low muscle mass. The reverse mismatch happens in muscular people. When they disagree, clinicians use the combined equation and the urine albumin to decide.
Do I need a doctor's order to test my egfr (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 eGFR (Cystatin C) results?
Most eGFR (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 eGFR (Cystatin C) test cost?
Our Renal Panel starts at $23.99. 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 eGFR (Cystatin C) test?
Fasting is not required for the eGFR (Cystatin C) test. You can have your blood drawn any time of day.
Which lab will process my eGFR (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.
What can throw off a eGFR (Cystatin C) result?
Dehydration, creatine supplements and ibuprofen and other NSAIDs can change a eGFR (Cystatin C) result without anything being wrong. Dehydration can lower eGFR — repeat well-hydrated before acting on a low eGFR. Creatine supplements can falsely lower eGFR — do not accept a 'stage 2/3 CKD' label on creatinine alone while on creatine — confirm with cystatin C. Ibuprofen and other NSAIDs can lower eGFR — A low eGFR on daily NSAIDs plus dehydration is repeated off both before it is labelled kidney disease. Each is explained on our physician-reviewed "Before your test" pages; when one applies, remove it and retest.
Ready to test your egfr (cystatin c)?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $23.99.