Cosyntropin
Also known as: Cortrosyn, Tetracosactide, ACTH 1-24, Synacthen
Synthetic ACTH (1-24) used for the ACTH stimulation test to diagnose adrenal insufficiency. FDA-approved as Cortrosyn. Prescription diagnostic agent.
Last updated
Mechanism of Action
Cosyntropin consists of the first 24 amino acids of ACTH, the portion that carries full biological activity at the adrenal melanocortin-2 receptor. A standard dose rapidly stimulates the adrenal cortex to release cortisol. Measuring cortisol before and 30-60 minutes after injection shows whether the adrenal glands can respond normally, which is the basis of the cosyntropin (Synacthen) stimulation test.
- Half-life
- ~15 minutes (plasma)
- Administration Routes
- Intravenous, Intramuscular
- Research Status
- Clinical
Reported Benefits
- Diagnostic screening for primary adrenal insufficiency (Addison disease)
- Helps assess secondary (pituitary) adrenal insufficiency, with lower sensitivity in recent-onset disease
- Shorter peptide with lower allergenic potential than animal-derived ACTH
Potential Side Effects
- Hypersensitivity reactions, rarely anaphylaxis
- Flushing, nausea, transient tachycardia
- Injection-site reactions
Common Dosing
Administered by clinical staff as a single intravenous or intramuscular dose (standard test 0.25 mg) with blood cortisol drawn at baseline and at 30 and/or 60 minutes; a low-dose variant is used in some centers. Testing is ordered and interpreted by the clinician.
The dosing information above is aggregated from research literature and anecdotal community reports for educational purposes only. It is not a recommendation, prescription, or medical advice. Peptides are sold as research chemicals only and are not intended for human use.
Contraindications
- Known hypersensitivity to cosyntropin
- Interpretation is unreliable during recent glucocorticoid use or with altered cortisol-binding globulin (e.g., oral estrogen)
No documented stacking partners for Cosyntropin yet.