Approved

Cosyntropin: Uses, Evidence, and Reported Side Effects

Drafted by an automated content engine from FDA, PubChem, ClinicalTrials.gov, NIH DSLD, and Open Beauty Facts data.

Molecular formulaC136H210N40O31S
Molecular weight2933.4 g/mol
Registered trials96
PubChem CID16129617
Drug classAdrenocorticotropic Hormone [EPC]
Brand namesCosyntropin

If a doctor has ordered a test for adrenal function, cosyntropin may be the agent used to perform it. This synthetic hormone is given to check how well the adrenal glands respond, rather than to treat a disease directly.

Key takeaways

  • Cosyntropin is classified as an adrenocorticotropic hormone used as a diagnostic agent.
  • It is approved to help screen for adrenocortical insufficiency by prompting a cortisol response.
  • The label describes a rapid-acting test that can be completed in about 30 minutes with two venipunctures.
  • Cosyntropin (brand name Cosyntropin) carries no boxed warning.
  • More than 90 registered trials have studied cosyntropin, largely in the context of adrenal suppression testing.

What Cosyntropin Is

Cosyntropin belongs to the adrenocorticotropic hormone drug class. It is designed to act on the adrenal cortex, prompting it to produce cortisol so clinicians can assess how the adrenal glands are functioning.

What Cosyntropin Is Approved For

Cosyntropin for Injection is approved as a diagnostic agent to screen patients suspected of having adrenocortical insufficiency. Because it acts quickly on the adrenal cortex, it can be used to run a short, roughly 30-minute test of adrenal function that measures plasma cortisol response. The label notes that a low basal cortisol level alone is not enough to confirm insufficiency, since many affected patients have normal baseline levels and show problems only when the body is under stress. This is why the test measures the cortisol response to cosyntropin rather than relying on a single baseline value. The approved product is marketed under the brand name Cosyntropin, and its label does not carry a boxed warning.

What the Evidence Shows

Cosyntropin has been studied in 96 registered trials. Several of these have focused on whether other medications suppress the hypothalamic-pituitary-adrenal axis, using cosyntropin testing as the measurement tool. One completed Phase 2 study compared a topical cream against clobetasol propionate cream for HPA axis suppression in patients with moderate to severe plaque psoriasis. Another completed Phase 2 study evaluated the adrenal suppression potential of a topical product in pediatric patients with atopic dermatitis, again using cosyntropin-based testing as the outcome measure.

Reported Side Effects

Reported cases submitted to a safety surveillance database reflect report counts, not confirmed incidence or causation. The most frequently reported issues involve pregnancy-related exposure findings, including foetal growth restriction (24 reports) and foetal exposure during pregnancy (23 reports). Metabolic and cardiovascular reports follow, including hypoglycaemia (20), hypotension (18), and hyperkalaemia (11). Respiratory and general reports include dyspnoea (13), pneumonia (13), and nausea (12).

FAQ

What is cosyntropin used for?
Cosyntropin is used as a diagnostic agent to screen for adrenocortical insufficiency. It works by prompting the adrenal cortex to release cortisol, allowing clinicians to measure how well the adrenal glands respond. It is not used to treat a disease directly.
How does the cosyntropin test work?
The label describes cosyntropin as acting rapidly on the adrenal cortex, allowing a test of adrenal function to be completed in about 30 minutes using two venipunctures. Clinicians measure plasma cortisol before and after the dose to assess adrenal response.
Does cosyntropin have a boxed warning?
No, the cosyntropin label does not carry a boxed warning.
What side effects have been reported with cosyntropin?
Reported cases include pregnancy-related exposure findings, hypoglycaemia, hypotension, hyperkalaemia, dyspnoea, pneumonia, and nausea. These figures come from a safety surveillance database and reflect report counts, not confirmed rates or proof that cosyntropin caused the event.
Is a low baseline cortisol level enough to diagnose adrenal insufficiency?
No, the label notes that a low basal cortisol level alone is not sufficient evidence of adrenal insufficiency. Many patients with confirmed insufficiency have normal baseline levels and only show abnormal responses when tested with cosyntropin or when physically stressed.
This page is an editorial information resource. It does not sell, prescribe, or recommend any medication. Content is editorial information, not medical advice. Talk to your doctor before any treatment decision.

Sources: FDA drug label (DailyMed) ClinicalTrials.gov FDA Adverse Event Reporting System (FAERS) PubChem

Updated 2026-08-10