Cosyntropin
Cosyntropin is a research peptide in the Melanocortin receptor agonist class. The N-terminal 24 residues of ACTH carry its full biological activity at the melanocortin-2 receptor of the adrenal cortex, while the omitted C-terminal residues account for most of the immunogenicity of the full hormone.
For research use only.
Key Facts
- CAS
- 16960-16-0
- Molecular Weight (MW)
- 2933.4 g/mol
- Half-life
- —
- FDA status
- Approved
- Administration Route
- intravenous, intramuscular
- Frequency
- —
- Last updated
- Aug 30, 2026
- Reviewed
- Aug 30, 2026
Research summary
Synthetic peptide comprising the first 24 amino acids of corticotropin, approved as a diagnostic agent for screening adrenocortical insufficiency. It is a diagnostic tool rather than a therapy.
Peptide Library's Cosyntropin profile summarises 5 cited studies listed in the Science section, the compound's regulatory status, and research-protocol parameters reported for it. It is a research reference, not medical advice.
Protocol
- Dosage Range
- —
- Frequency
- —
- Cycle
- —
- Administration Route
- intravenous, intramuscular
- Reconstitution Guide
- —
Not yet checked against primary sources
These figures are compiled from earlier reference material. They have not been verified against FDA labelling, registered trials or published literature, no citation is attached to them, and none of them is a recommended dose. Cosyntropin is queued for dosage evidence review.
Compare reported doses across the whole librarySequence & molecular data
| Molecular formula | C136H210N40O31S |
|---|---|
| Molecular weight | 2933.4 g/mol |
| CAS number | 16960-16-0 |
| PubChem CID | 16129617 |
Identifiers link to the public PubChem, FDA Substance Registration (UNII), ChEMBL and DrugBank records for the same entity.
Science
Mechanism of Action
The N-terminal 24 residues of ACTH carry its full biological activity at the melanocortin-2 receptor of the adrenal cortex, while the omitted C-terminal residues account for most of the immunogenicity of the full hormone. Receptor activation raises cyclic AMP and stimulates steroidogenesis, so the cortisol rise after a measured dose reports the adrenal cortex’s capacity to respond.
Studies
- Adrenal venous sampling: cosyntropin stimulation or not?
- Prevention of post-dural puncture headache in parturients: a systematic review and meta-analysis
- Cosyntropin-Stimulated Aldosterone Reserve of the Nondominant Adrenal Predicts Surgical Outcomes in Primary Aldosteronism
- Intra-Lot and Inter-Lot Variability in Cosyntropin
- Comparative effects of methylprednisolone and tetracosactide (ACTH(1-24)) on ischemia/reperfusion injury of the rabbit spinal cord
Regulatory & research status
Cosyntropin is an FDA-approved product for specific labelled indications. Approval does not extend to the research contexts described on this page, and approved products are prescription medicines.
| FDA status | Approved |
|---|---|
| Research status | Approved product (see FDA status) |
| Availability | Prescription-Only |
| WADA (sport) | Unknown / Not Listed |
| Library classification | FDA-Approved |
Benefits
—
Potential Side Effects
No side effects listed yet for this entry.
Storage & stability
Lyophilized (freeze-dried) peptide powder is far more stable than the reconstituted solution. Keep sealed vials cold, dry and away from light; long-term storage is typically frozen, with short-term refrigeration for vials in use.
Once reconstituted in bacteriostatic water, keep the solution refrigerated, avoid repeated freeze–thaw cycles and agitation, and label the vial with the reconstitution date and concentration. Discard any solution that turns cloudy or shows particulates.
Degradation rates differ by sequence: peptides containing methionine, cysteine, asparagine or glutamine are more prone to oxidation and deamidation, so shelf life after reconstitution is compound-specific rather than universal.
Read the full guide: how to store peptides before and after reconstitution →
Source: Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544–575. (PMID 20143256). General guidance for research handling; not product-specific instructions.
Cosyntropin: frequently asked questions
What is Cosyntropin?
Synthetic peptide comprising the first 24 amino acids of corticotropin, approved as a diagnostic agent for screening adrenocortical insufficiency. It is a diagnostic tool rather than a therapy.
How does Cosyntropin work?
The N-terminal 24 residues of ACTH carry its full biological activity at the melanocortin-2 receptor of the adrenal cortex, while the omitted C-terminal residues account for most of the immunogenicity of the full hormone. Receptor activation raises cyclic AMP and stimulates steroidogenesis, so the cortisol rise after a measured dose reports the adrenal cortex’s capacity to respond.
Is Cosyntropin FDA approved?
Yes. Cosyntropin is approved by the FDA, and approved products are prescription medicines. Approval is always for specific indications studied in clinical trials, so an approved status does not mean the compound is approved for every use it is discussed for. Research-chemical material sold under the same name is not the approved product.
What peptides are similar to Cosyntropin?
Compounds most often compared with Cosyntropin include Bremelanotide, Melanotan II, Angiotensin II and Cetrorelix. They are grouped by shared mechanism or research area rather than by equivalence, and their regulatory status and evidence base differ.
References
- Adrenal venous sampling: cosyntropin stimulation or not? — Eur J Endocrinol, 2019External reference
- Prevention of post-dural puncture headache in parturients: a systematic review and meta-analysis — Acta Anaesthesiol Scand, 2013External reference
- Cosyntropin-Stimulated Aldosterone Reserve of the Nondominant Adrenal Predicts Surgical Outcomes in Primary Aldosteronism — Hypertension, 2025External reference
- Intra-Lot and Inter-Lot Variability in Cosyntropin — Contact Context, 2021External reference
- Comparative effects of methylprednisolone and tetracosactide (ACTH(1-24)) on ischemia/reperfusion injury of the rabbit spinal cord — Arch Med Sci, 2018External reference
Related research, comparisons & guides
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Compiled by Peptide Library Editorial · Reviewed Aug 30, 2026 · Updated Aug 30, 2026 · Version 1
This Cosyntropin profile is compiled from published literature (5 cited studies linked above), public regulatory records and chemical registries. It describes what research reports; it is not medical advice, and nothing here is a dosing recommendation for humans. Peptide Library does not sell peptides. Editorial policy · How profiles are compiled · Report an error
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