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Beta C-Telopeptide (CTX) — Concentration

Published: August 9, 2026Updated: August 16, 2026

Measures beta C-telopeptide (CTX), a marker released during bone breakdown, to assess bone turnover and monitor treatment.

Quick summary

["CTX helps evaluate bone breakdown and may be used to monitor treatment for conditions that weaken bones."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
36443-0
Short code
CT Elbow WO contr
Synonyms
CT Elbow WO contr
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

Beta C-telopeptide, also called CTX or collagen cross-linked C-telopeptide, is a substance released when bone is broken down. The test measures its concentration in a laboratory sample.

Why might I need this test?

A clinician may order this test to evaluate bone turnover, particularly in people with osteoporosis or other conditions that cause bone loss. It may also help monitor the response to medicines that reduce bone breakdown.

How is the test performed?

A laboratory analyzes a blood or urine sample, depending on the test ordered. The sample is measured to determine the amount of CTX present.

How do I prepare for the test?

Follow the laboratory's instructions for the required specimen. If fasting or a specific collection time is requested, follow those instructions exactly; otherwise, normal preparation usually applies.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A higher CTX level may indicate that bone is being broken down faster than usual, as can occur with postmenopausal bone loss and some other high-turnover bone disorders. Lower or suppressed levels may be seen with effective antiresorptive treatment. Results should be interpreted with other bone-density tests, medical history, and medications.

Short name

Beta C-telopeptide (CTX)

Frequently asked questions

What does a CTX level tell me?
CTX reflects the rate at which bone is being broken down. It is used to assess bone turnover rather than to diagnose osteoporosis by itself.
Why is CTX sometimes checked more than once?
The level may be measured over time to check whether treatment is reducing bone breakdown. Trends can sometimes be more informative than a single result.
Does an abnormal CTX result mean I have osteoporosis?
No. An abnormal result may suggest increased or reduced bone turnover, but it must be interpreted alongside bone-density testing, symptoms, medical history, and other laboratory results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy