Cosyntropin
Also known as: Cortrosyn, ACTH 1-24, Tetracosactide
At a glance
PeptiGuide dataset · reviewed Aug 2026
What it is
Synthetic ACTH 1-24 peptide used to evaluate adrenal cortisol response.
Status
FDA Approved
Typical dose
250mcg
Researched for
Adrenal function testing, diagnostic use
Trial progress
- PrePreclinical
- IPhase I
- IIPhase II
- IIIPhase III
- IVPhase IV
- FDAFDA approved
FDA approved - FDA-approved for specific uses with established human evidence
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In plain language
- Synthetic ACTH 1-24 fragment used for adrenal function testing.
- Source status: FDA Approved; clinical status: FDA Approved - Diagnostic use.
- Administration is listed as IV or intramuscular, with community dose data described as limited.
- Research/label dosing row lists 250 mcg IV/IM as a standard single diagnostic dose.
- Researched for adrenal function testing and diagnostic use.
How it's thought to work
Cosyntropin is the 1-24 amino-acid portion of ACTH, while endogenous ACTH is described as 39 amino acids long. The source reports that this fragment activates the melanocortin-2 receptor on adrenal cortex cells, which can produce a rapid cortisol rise; the diagnostic value comes from observing whether the adrenal response occurs as expected.
What the research shows
Where the research stands
The source characterizes cosyntropin as an FDA-approved, clinically established diagnostic agent. It reports a standard adult diagnostic dose of 250 micrograms, also expressed as 0.25 mg, administered IV or intramuscularly. The described testing approach measures serum cortisol before dosing and again at 30 and 60 minutes. A response reaching roughly 18 micrograms per deciliter is described as generally normal, while assay choice can shift thresholds, including lower cutoffs with LC-MS/MS. A weak cortisol rise may support adrenal insufficiency assessment, with the source distinguishing primary adrenal disease from possible secondary or tertiary causes and noting interpretation caveats. The evidence focus is diagnostic accuracy and test interpretation, not therapeutic benefit.
What it shows
✓ Human clinical evidence
FDA-approved for specific uses with established human evidence
△ Limitations
Use only according to approved labeling and qualified medical guidance.
Bottom line: FDA Approved - Diagnostic use FDA Approved
Typical dosing
CommunityCommunity datasetLimited community data available
See research protocols
Range: See research dosing
Research dosing
Indication-specificApproved for specific uses - study doses are indication-specific
Timing & administration
Best time to take
Morning or as directed
Follow recommended protocol
Food recommendation
With or without food
Why this timing?
The source gives protocol-following as the timing guidance and notes that timing may depend on response and goals; it also emphasizes consistent timing over a particular clock time.
Possible side effects
Not everyone experiences these. Individual responses vary with dose, duration, and personal factors.
- Hypersensitivity reactions
- Injection site reactions
- Bradycardia or tachycardia
- Blood pressure changes
- Headache
- Intended for diagnostic use
- FDA approved (Cortrosyn)
Not everyone experiences side effects, and severity can vary by context, purity, route, and individual health factors.
Frequently asked questions
Sequence
SYSMEHFRWGKPVGKKRRPVKVYP (ACTH 1-24)
One open dataset
Every fact on this page - doses, side effects, references - comes from the same PeptiGuide dataset that powers the Tracker, Compare, and the Lab.
Browse the datasetEducational resource, not medical advice. Talk to your clinician before acting on anything here.
Community discussion
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