Peptide LibraryCosyntropin
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
- Evidence level
- FDA Approved
- Human dose established
- Yes
- Administration Route
- Intravenous · Intramuscular
- Frequency
- Single dose per test
- Last updated
- Nov 7, 2026
- Reviewed
- Nov 7, 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.
Research evidence
- Regulatory review (FDA label)2 reviewed sources
- Controlled human trialsNone in reviewed sources
- Early or uncontrolled human studiesNone in reviewed sources
- Lab & animal studiesNone in reviewed sources
How it works
Each step shows whether the sources Peptide Library has reviewed include that kind of research. Counts are reviewed sources, not every study ever published. Reviews and programme summaries that describe human use are shown as "reported", not as trials, and registered trials without published results are listed but not counted. A higher step means research has progressed further; it does not mean a compound works better or is safer. Compounds whose evidence has not been reviewed yet show "Not reviewed" instead of a guess.
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.
Cosyntropin dosage evidence
Cosyntropin has an FDA-approved human dosage as a single diagnostic dose for screening adrenocortical insufficiency. The CORTROSYN label dose is 0.25 mg by intravenous or intramuscular injection for adults and children aged 2 to 17, and 0.125 mg from birth to under 2 years, with serum cortisol measured at baseline and at 30 and 60 minutes.
| Human dosing established | Yes |
|---|---|
| Route | Intravenous · Intramuscular |
| Frequency | Single dose per test |
| Duration studied | One diagnostic test |
| Evidence level | FDA Approved |
| Last reviewed | 2026-11-07 |
Research-reported dosing
Doses as studied, one row per regimen. Different trials used different regimens; they are listed separately rather than averaged.
| Study / context | Population | Dose | Route | Frequency | Duration | Outcome studied | Source |
|---|---|---|---|---|---|---|---|
| FDA label — CORTROSYN, adultsFDA-approved label · FDA prescribing information | Adults being screened for adrenocortical insufficiency | 0.25 mg | Intravenous or intramuscular | Once | Cortisol sampled at baseline and exactly 30 and 60 minutes after the dose | Diagnostic cortisol response, interpreted with other tests | CORTROSYN (cosyntropin) for injection — FDA prescribing information (Amphastar), DailyMed |
| FDA label — CORTROSYN, pediatric patientsFDA-approved label · FDA prescribing information | Children from birth to 17 years being screened for adrenocortical insufficiency | 0.125 mg (0.5 mL) from birth to under 2 years; 0.25 mg (1 mL) from 2 to 17 years | Intravenous or intramuscular | Once | Cortisol sampled at baseline and exactly 30 and 60 minutes after the dose | Diagnostic cortisol response, interpreted with other tests | CORTROSYN (cosyntropin) for injection — FDA prescribing information (Amphastar), DailyMed |
Where sources disagree
- Cosyntropin is a diagnostic agent, not a treatment. The label says to stop glucocorticoids and spironolactone on the day of testing (longer for long-acting glucocorticoids) and estrogen-containing drugs four to six weeks before, because they can make the result inaccurate.
- The label warns of hypersensitivity reactions, including anaphylaxis.
- COSACTHEN, also listed on DailyMed under cosyntropin, is a veterinary product (Dechra) and contributes no human dosing here.
Sequence & 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
Research statistics
2,701 PubMed publications · 54.5% human clinical research · 39 registered trials
Counts of published research through 2026-11-01, not evidence that it works. Publications by year, study types and trials · How publications are counted
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 |
How FDA approval, compounding and research-only status differ
Benefits
—
Cosyntropin side effects
No side effects listed yet for this entry.
Storage & stability
This compound is not supplied as a powder to be mixed, so the freeze-dried powder and reconstitution handling described for research peptides does not apply. Storage conditions are product-specific: follow the label or packaging of the product itself.
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 Nov 7, 2026 · Version 2
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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