Collagen Cross-Linked N-Telopeptide (NTx), Urine Test
A collagen cross-linked N-telopeptide, or NTx, urine test measures a marker of bone turnover in a urine sample. Clinicians use this marker to help evaluate the pace at which bone tissue is being remodeled over time.
About this test
Bone is living tissue that is constantly renewed: old bone is broken down while new bone is built, an ongoing process called remodeling. When bone is broken down, small fragments of a structural protein called collagen are released, and NTx is one of those fragments.
Unlike many lab tests, this one uses a urine sample rather than a blood draw. The sample is collected at a Quest patient service center, and people follow any instructions their ordering clinician provides about timing or preparation, since collection details can matter for markers like this.
Who might consider this test?
- Others come to the topic curious about how bone renewal is tracked and how it differs from a density scan.
Test details
| Quest code | 36167 |
|---|---|
| Methodology | Chemiluminescence |
| Sample type | 2 mL unpreserved urine collected from second morning void |
| Collection | Quest patient service center |
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Additional details
What this test looks at
The test looks at NTx, a collagen fragment released when bone is broken down as part of normal remodeling. Because that fragment appears in urine, its measurement gives a clinician a sense of how active the breakdown side of the cycle is. The reading reflects a rate of turnover, capturing motion in the system rather than a static snapshot of how much bone exists.
That focus on rate is the key distinction. A density scan answers a different question about bone quantity, while a turnover marker like NTx speaks to how briskly bone is being remodeled, which is why the two are often thought of as complementary rather than interchangeable.
How it is often used
Clinicians commonly use bone-turnover markers to follow change over time. Because a single measurement has limited meaning on its own, NTx is frequently most useful when a clinician compares results across a series, watching for trends within the context of a person's overall care. It is one input a clinician weighs alongside history, imaging, and other markers rather than a decision-maker by itself.
Order online and a physician order is included — no doctor's visit and no insurance needed. Your sample is collected at a Quest Diagnostics patient service center.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does the NTx urine test measure?
It measures N-telopeptide, a collagen fragment released when bone is broken down during normal remodeling. The marker helps a clinician evaluate the pace of bone turnover over time.
Is this a blood test?
No. NTx here is measured in a urine sample collected at a Quest patient service center, so no blood draw is involved for this particular test.
Is NTx the same as a bone density scan?
No. A density scan looks at how much bone is present, while NTx reflects how actively bone is being remodeled. Clinicians often view the two as complementary rather than interchangeable.
Why is NTx often measured more than once?
Turnover markers are frequently most useful as a trend. A clinician may compare results across a series to see how the pace of remodeling changes, rather than relying on a single measurement.
Do I need to prepare?
Follow any timing or preparation instructions your ordering clinician provides, since collection details can matter for turnover markers. Individual situations and reasons for testing vary.
Can I get the Collagen Cross-Linked N-Telopeptide , Urine test without a doctor's visit or insurance?
Yes. The $379 cash price includes an independent physician's order, so no referral is needed, and insurance is never involved.