A patient seated in the chair before a blood draw
In person

Creatinine

A kidney function marker with eGFR, from one blood draw.

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  • 2,000+ lab locations. Find one near you
  • Nothing due at the lab. FSA / HSA accepted
  • Ordered by a licensed clinician

At a glance

Collection
Blood draw
A standard blood draw at the lab.
Preparation
None
Nothing to do ahead of time. Water is fine.
Results
1 to 2 days
Typical turnaround after your visit.
Where
2,000+ lab locations
Nationwide, with nothing due at the lab.

About this test

Creatinine is a waste product from everyday muscle use that your kidneys filter out of the blood. Your report also shows eGFR, an estimate of how well your kidneys filter, calculated from creatinine, age, and sex. It is often checked with blood pressure care or medicines. No fasting is needed.

For adults 18 and older. Test availability varies by lab location.

Who should take this test?

This test is for adults who want to check kidney function, often alongside blood pressure or diabetes care, during medication check-ins, or as a yearly baseline.

Ask about this test

Not sure this is the right test?

AI-generated. For information only, not medical advice. Call 911 for an emergency.

What does this test measure?

Your result shows your creatinine and eGFR, which can help you and a healthcare provider see how well your kidneys are filtering and follow that over time.

Creatinine
Creatinine is a waste product made at a fairly steady rate by your muscles and removed by your kidneys. Because the kidneys clear it, the level in your blood helps show how well they are filtering. Muscle mass, age, and sex affect the usual level, so it is read in context.
Why it’s measured: A common measure of kidney filtering, and the basis for eGFR.
Estimated glomerular filtration rate (eGFR)
eGFR is not measured directly. The lab calculates it from your creatinine result along with your age and sex to estimate how much blood your kidneys filter each minute. It gives a clearer view of kidney function than creatinine alone, and a provider reads it over time.
Why it’s measured: To estimate kidney filtering from your creatinine, age, and sex.

How it works

  1. Step 1

    Order online

    Check out here. A licensed clinician in your state reviews your order and sends it to the lab.

  2. Step 2

    Visit a lab

    Bring a photo ID to any of 2,000+ lab locations. No fasting needed, and nothing is due at the lab.

  3. Step 3

    Get your results

    Results post to your account, usually in 1 to 2 days, each number next to the lab’s reference range.

Find a lab near you

Choose from 2,000+ lab locations nationwide. Your order works at any of them.

What your results tell you

Creatinine is reported in milligrams per deciliter (mg/dL) and eGFR as an estimated filtration rate. Both are compared with the lab’s range.

  • Each marker next to the lab’s reference range
  • Explained in plain language
  • A licensed clinician reviews your order and, if appropriate, orders the test.
  • A lab report you can download and share

Kidney function is judged over time and with other tests, so talk with a healthcare provider about your result and whether to recheck it.

Clinical-grade testing, from the comfort of home.

From the lab to your report, every step of our process meets the gold standard in medical testing.

  • CLIA-certified labs

    Every lab we partner with is certified under the Clinical Laboratory Improvement Amendments, meeting both state and federal standards with regular independent inspections.

  • We protect your health data

    We protect your health data with encryption and do not sell it. Some results must be reported to public health authorities by law. See our Privacy Notice.

  • Rigorous quality assurance

    All partner labs run regular internal quality checks, participate in proficiency testing, and comply with federal and state lab regulations.

  • Clinician-reviewed reports

    Results are reviewed by an independent, licensed clinician.

Questions

Common questions.

Anything else, our care team answers by phone, text, or email.

eGFR stands for estimated glomerular filtration rate. It is calculated from your creatinine result, age, and sex to estimate how much blood your kidneys filter. Because it adjusts for those factors, eGFR is often easier to compare than creatinine alone.

It is still an estimate that a healthcare provider reads with your history.

Creatinine comes from muscle, so it tends to be higher in people with more muscle and lower in people with less. It also varies with age and sex, which is why eGFR adjusts for both. Hydration on the day of the test can shift it too.

Not necessarily. Creatinine is not sensitive to early kidney changes, so a result within the reference range does not exclude reduced kidney function. That is why eGFR is reported with it, and why a urine albumin test is often added when kidney health is a question.

Lab tests are informational and don’t diagnose conditions on their own. Available to adults 18 and older; test availability varies by lab location. A licensed clinician reviews your order and, if appropriate, orders the test. All testing is performed at CLIA-certified laboratories. Not for emergencies: if you think you may be having a medical emergency, call 911.