CosyntropinDiagnostic peptide
Cosyntropin is a synthetic fragment of ACTH used to stimulate cortisol production during testing. The information comes from the body’s measured response, interpreted in the clinical context.
What is Cosyntropin?
Cosyntropin, also called tetracosactide, is a synthetic fragment containing the first 24 amino acids of ACTH. It is commonly used to test adrenal cortisol responsiveness rather than as a treatment for fatigue. 1 2
How it works
It stimulates the adrenal cortex. Cortisol is measured at defined times to assess the response, with interpretation depending on the protocol and laboratory assay. 1 2
Effects studied
What does the evidence show?
Established diagnostic role; archived protocol research retained
A controlled signal to the adrenal glands
Cosyntropin, also called tetracosactide, contains the first 24 amino acids of ACTH. This fragment can stimulate the adrenal cortex. In a diagnostic setting, it provides a defined signal so clinicians can observe how cortisol production responds.
Before and after, under defined conditions
The test compares cortisol measurements taken around administration according to a specified protocol. Timing, assay and the appropriate reference threshold matter. A number copied from another laboratory or test method may not have the same interpretation. This is why the procedure cannot be reduced to one universal “good cortisol” value.
What a response cannot settle alone
A blunted response can support investigation of adrenal insufficiency. Interpreting the cause also involves symptoms, other hormone results, medication history and the clinical timeline. The response does not automatically distinguish every pituitary, hypothalamic or adrenal disorder without that additional information.
Testing is different from treatment
Cosyntropin’s diagnostic use should not be confused with ongoing corticotropin therapy or with a treatment for everyday tiredness. Allergic reactions and transient cardiovascular or other effects are possible, even though the exposure is brief. In a supervised assessment, the test makes the hormonal response measurable. Raising cortisol is not itself a personal health objective.
Safety & status
Hypersensitivity and transient cardiovascular reactions can occur. The testing context and interpretation matter as much as the administration of the peptide. 2
Country and product status
Country-specific product availability and authorisation require a separate current check.
Frequently asked questions
Does a single cortisol cut-off work for every test?
No. Assay methods, timing and the testing protocol affect the interpretation. 1
Does the test treat low energy?
No. It measures a hormonal response; it is not a general fatigue therapy. 2
Sources
This entry was rewritten from our research archive. References below are reading leads unless a completed check is explicitly noted; a full independent evidence and regulatory review is still pending.
- Cosyntropin · retained archive reference Archive research lead · Retained archive reference; not independently checked for this draft
- Cosyntropin · retained archive reference Archive research lead · Retained archive reference; not independently checked for this draft
Research provenance
This name was discovered in the Superpower peptide index, archived 26 October 2026. Its ratings and reviewer attribution have not been adopted as our own. The archive informed this original editorial draft; independent source review is still pending.