Evidence review: Open Peptide Project (verified against primary PubMed, ClinicalTrials.gov & FDA records) · Last checked 2026-10-27. ← Back to Evidence Library

Cosyntropin (Cortrosyn, tetracosactide, ACTH 1-24): what the evidence says

Name: Cosyntropin (Cortrosyn, tetracosactide, ACTH 1-24)
Published: 2026-10-27

At a glance

What it is: a synthetic peptide made of the first 24 of the 39 amino acids of human ACTH, which carries ACTH's full cortisol-stimulating activity. Approved as Cortrosyn (Apr 1970) as a diagnostic agent: blood cortisol is measured before and after a dose to screen for adrenal insufficiency. Synacthen is a brand used outside the US. ^{R1, R2, R3}

What the evidence says: Human a meta-analysis found high- and low-dose ACTH stimulation tests had similar accuracy; both are good at confirming secondary adrenal insufficiency but can miss it, and confidence in the estimates was low to moderate. ^R4

Biggest risks: allergic reactions including anaphylaxis; certain medicines and conditions that change cortisol-binding protein can make results inaccurate. Prohibited in sport. ^{R3, R5}

Rating


Human Human evidence	Moderate: diagnostic-accuracy meta-analysis ^R4
Animal Animal / lab evidence	Not reviewed
Regulatory	FDA-approved ^R1 · not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page ^{R6, R7, R8} · prohibited at all times (WADA S2.2.2) ^R5
Established human dose	Yes, label dose (see Study details)

Evidence verdict: Testing for adrenal insufficiency: Moderate (diagnostic-accuracy meta-analysis; good at ruling in, weaker at ruling out) · Treatment of any condition: not a treatment in the US

This page reports what studies used. It is not dosing advice.

Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source

About the evidence: pooled diagnostic studies with varied cortisol cut-offs; the test is a screen and is used with other tests.

What is it?

Related pages: corticotropin-acth.

Does it work?

Human Secondary adrenal insufficiency (30 studies, 1,437 people): positive likelihood ratios 9.1 (high dose) and 5.9 (low dose) in adults; negative likelihood ratios weaker. ^R4
Human Primary adrenal insufficiency (5 studies, 100 patients): sensitivity 92% for the high-dose test. ^R4

Is it safe?

Warnings: hypersensitivity including anaphylaxis; diagnostic inaccuracy with some medicines. ^R3
Most common: anaphylactic reaction, slow or fast heart rate, high blood pressure, swelling, rash. ^R3

Gray-market vials: extra risks

A gray-market vial has no quality control and no guarantee of identity, strength or sterility. We test retail vials blind under the Open Peptide Standard; see /tests/. A passing test covers one batch on one date and does not mean the compound is safe.

Is it legal?

US: FDA-approved, prescription diagnostic (Cortrosyn; generic cosyntropin). ^{R1, R2}
Compounding: not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page. ^{R6, R7, R8}
Sport: prohibited at all times; WADA names tetracosactide (cosyntropin) under S2.2.2. ^R5

Study details

These are amounts researchers used, not recommendations.

Study	People / model	Route	Amount used	Follow-up	Reported	Citation
Ospina 2016 meta-analysis	30 studies (secondary AI) + 5 (primary AI)	IV or IM	250 µg (high dose) vs 1 µg (low dose)	Single test	Similar accuracy; good to rule in, weaker to rule out	PMID 26649617
Cortrosyn label	Adults and children	IV or IM	Per label	Single test	Approved for adrenal insufficiency screening	^R3

Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 27, 2026)

^R1 Drugs@FDA, Cortrosyn (cosyntropin), application NDA016750 (openFDA drugsfda record checked Oct 27, 2026). https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=NDA016750
^R2 Drugs@FDA, Cosyntropin (Sandoz), application ANDA202147 (openFDA drugsfda record checked Oct 27, 2026). https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=ANDA202147
^R3 Cortrosyn prescribing information, label published Feb 7, 2025 (DailyMed, checked Oct 27, 2026). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=746856e9-3930-4f6a-b8e6-a03845d6dd0b
^R4 Ospina NS, et al. J Clin Endocrinol Metab. 2016. PMID 26649617
^R5 WADA. The 2026 Prohibited List, S2.2.2, Corticotrophins and their releasing factors, naming tetracosactide. https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf
^R6 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download
^R7 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download
^R8 FDA, Certain bulk drug substances for use in compounding that may present significant safety risks (content current Apr 22, 2026). https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks

Disclaimer

This page is for education and harm reduction, not medical advice or a recommendation to use Cosyntropin (Cortrosyn, tetracosactide, ACTH 1-24). This is a prescription medicine. Use it only under the care of a licensed clinician; do not buy it from research-chemical or gray-market sellers. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).