What it is
Copeptin is the C-terminal part of the vasopressin precursor, a 164-residue protein whose processing is mapped in UniProt (P01185). The 39 residues at positions 126–164 are released alongside vasopressin, the hormone that helps the kidney hold on to water.
Why it is measured
Vasopressin is hard to measure accurately in blood: it is short-lived. Copeptin is released in the same amount and is more stable, so the lab measures it as a proxy. That is the standard reason the fragment became a clinical marker. The reasoning is established; the performance of any single test should be taken from the lab's own validation.
What the record covers
A PubMed search on 2026-11-09 for copeptin together with chest pain or myocardial infarction and diagnosis terms returned 211 records. The individual trials were not opened for this entry, so the page gives the count and not a verdict on how well the test performs. Clinicians use it alongside other tests; no single marker is a diagnosis. For another blood marker used in heart assessment, see BNP and NT-proBNP.
What the evidence does and does not show
- Structure: the fragment map is from UniProt. Well established.
- Use as a stress-hormone marker in blood: an established lab measurement, studied in chest-pain assessment.
- Use as a treatment: not a treatment, and no therapeutic trial was located.
A copeptin result is a clinical measurement, not a self-test. A reader who has one should take it to the clinician who ordered it.
Where it stands
| Question | Answer as of 2026-11-09 |
|---|---|
| Fragment | 39 residues, positions 126–164 (UniProt P01185) |
| Use | Blood measurement by a clinical lab |
| Published record | 211 chest-pain or myocardial-infarction records (PubMed, 2026-11-09) |
| Advice | None given here |
Related reading
For the hormone it is released with, see the vasopressin entry. For the other natriuretic peptides measured in the same clinical setting, see the natriuretic-peptides entry.