Approved drugSynthetic ACTH (1–24), diagnostic agent

Cosyntropin

Cortrosyn, Synacthen, Synacthen Depot; tetracosactide (tetracosactrin); ACTH 1–24

Common dose: 0.25 mg once (test)
Cycle: As needed
Form: Ready-made product

The first 24 of the 39 amino acids of ACTH, the pituitary hormone that tells the adrenal glands to make cortisol. One injection shows whether the adrenal glands can respond by raising cortisol.

Evidence. FDA-approved since 1970 (Cortrosyn, now also generics) as a one-off test of adrenal function in adults and children. Abroad it is sold as Synacthen for the same test, and as Synacthen Depot, a slow-release injection used for longer adrenal tests and, depending on the country, short-term treatment of steroid-responsive conditions, multiple sclerosis flare-ups or infantile spasms.

What it’s used for

Approved uses first, then uses tested in people, then claims that rest on animal studies or user reports.

Testing for adrenal insufficiency: LabelApproved in the US and abroad as a one-off test: cortisol is measured before and 30–60 minutes after an injection, and a level under 18 mcg/dL suggests the adrenal glands aren’t responding normally.
Inflammatory bowel disease and arthritis flares: LabelUK only: Synacthen Depot is licensed for short-term use where steroids would be used, such as ulcerative colitis, Crohn’s disease or rheumatoid arthritis, especially when steroid pills don’t suit.
Multiple sclerosis flare-ups: LabelLicensed in Australia as Synacthen Depot for acute relapses of multiple sclerosis. Not an approved use of cosyntropin in the US or UK.
Infantile spasms in children: LabelLicensed in Australia (Synacthen Depot). In the UKISS trial of 107 infants, spasms stopped by day 14 in 73% on hormone treatment (76% with tetracosactide) vs 54% on vigabatrin.
Low-dose (1 mcg) adrenal test: TrialOff-label: a meta-analysis found the 1 mcg and 250 mcg tests about equally accurate for pituitary-related adrenal insufficiency; both are better at confirming it than ruling it out.
Headache after spinal or epidural puncture: TrialMixed: one 1 mg IV dose cut headaches after accidental dural puncture to 33% from 69% in a 90-woman trial (2010), but a 2025 trial found no benefit for established headaches.
Athletic performance or recovery: No studyUnproven: no study shows a performance benefit, and corticotrophins, including tetracosactide by name, are banned in sport at all times (WADA S2.2.2).

Label: an approved use. Trial: tested in people, with the result. No study: nothing published supports it.

Every compound’s uses, by body system: evidence map, and by condition: conditions A to Z.

Status

Approval: Approved in the US as Cortrosyn (since 1970) and generic cosyntropin, as a diagnostic test for adrenal insufficiency in adults and children. No US cosyntropin product is approved for treatment, and Synacthen Depot isn’t sold in the US.
Approval history: 1970US FDA: Cortrosyn: diagnostic test of adrenal function
1992Australia: Synacthen Depot: multiple sclerosis flare-ups and infantile spasms
2008US FDA: Cosyntropin solution: a ready-to-use liquid form; later discontinued
2009US FDA: Generic cosyntropin: first generic powder for injection approved
2021Canada: Synacthen Depot: no longer marketed (listed as dormant)
European Union: No EMA license; national prescription licenses only. In France, for example, Synacthène test ampoules are marketed, while the slow-release Synacthène Retard is authorized but not marketed.
United Kingdom: Prescription-only medicines licensed by the MHRA: Synacthen ampoules for the adrenal test, and Synacthen Depot for longer tests and short-term steroid-responsive conditions.
Canada: Prescription drug: Cortrosyn is marketed for adrenal testing. Synacthen Depot remains authorized but has been dormant (not sold) since July 2021.
Australia: Prescription only (Schedule 4). Synacthen for adrenal testing; Synacthen Depot for multiple sclerosis flare-ups and infantile spasms.
Sport (WADA 2026): Banned in sportS2.2.2 corticotrophins and their releasing factors, with tetracosactide named. Banned at all times.

Sport status follows the WADA Prohibited List in force since January 1, 2026; athletes should confirm with their anti-doping organization. Checked October 5, 2026. Status outside the US checked October 7, 2026 against EMA, MHRA, Health Canada and TGA records. By country: EU, UK, Canada, Australia. Status of every compound.

How it works

LabelBased on the product label.

Not known

Both the standard and low-dose tests can miss pituitary-related adrenal insufficiency, and the right cortisol cutoff depends on the lab’s assay. Effects of repeated depot treatment are mostly known from steroid-type side effects, not trials.

Protocol

Label

Cortrosyn and generics

Adults: 0.25 mg once, into a vein or muscle. Cortisol is measured just before and exactly 30 and 60 minutes after; a level under 18 mcg/dL at either time suggests adrenal insufficiency.

Label

Synacthen Depot (UK)

Adults: 1 mg into a muscle, with cortisol measured over 5 hours, when the short test is unclear; a 3-day version separates adrenal from pituitary causes.

Frequency: Once, as a test
Route: Intravenous or intramuscular injection (test dose); Synacthen Depot by intramuscular injection only (abroad)
Timing: The US label says to stop steroid medicines and spironolactone on the test day (long-acting steroids earlier) and estrogen-containing drugs 4–6 weeks before.
Cycle: A single test dose, not a course.
As needed, shown over 26 weeks

Common protocols

The ways Cosyntropin is most often run, each tagged with where it comes from.

Standard test (US)

Label

Dose: 0.25 mg
How often: Once, into a vein or muscle
How long: About 1 hour of blood draws

Cortisol at 0, 30 and 60 minutes. A level under 18 mcg/dL suggests adrenal insufficiency, though cutoffs vary with the lab’s assay.

30-minute Synacthen test (UK)

Label

Dose: 250 mcg
How often: Once, into a vein or muscle
How long: 30 minutes

Normal if cortisol rises by at least 200 nmol/L and is over 500 nmol/L at 30 minutes.

Low-dose test

Trial

Dose: 1 mcg
How often: Once
How long: Single test

Not on any label. In a meta-analysis it diagnosed pituitary-related adrenal insufficiency about as well as the 250 mcg test (Ospina 2016).

Synacthen Depot (abroad)

Label

Dose: 1 mg
How often: Once for the 5-hour test; as UK treatment, daily, then every 2–3 days
How long: Test: 5 hours or 3 days. Treatment: short term

Slow-release form, into a muscle only. UK: steroid-responsive conditions such as ulcerative colitis or rheumatoid arthritis; Australia: multiple sclerosis flare-ups.

Taking it

Where it goes

Into a vein or a muscle, given by a clinician (label). Synacthen Depot goes into a muscle only, never into a vein.

If you miss a dose

No missed-dose rule: it’s a single test dose given by a clinician. The US label calls for blood samples exactly 30 and 60 minutes after the injection.

Missed doses for every compound

What to expect

30–60 minutes
With healthy adrenal glands, cortisol rises; the US label treats a level under 18 mcg/dL at 30 or 60 minutes as suggesting adrenal insufficiency.
Label
30 minutes (UK test)
A normal response is a rise of at least 200 nmol/L, to over 500 nmol/L.
Label
5 hours (depot test)
With normal adrenal glands, cortisol doubles in the first hour and keeps rising, to 1,000–1,800 nmol/L by hour 5.
Label
Newer cortisol assays
In 110 patients tested with newer, more specific assays, the equivalent cutoff was 14–15 mcg/dL rather than 18; using 18 labeled about twice as many people abnormal.
Trial

Side effects and what to do

Allergic reactions, rarely anaphylaxis (label); more likely and more severe with asthma or other allergies (UK label)

Signs include hives, itching, flushing, faintness and breathlessness, usually within 30 minutes. Staff are prepared to treat them.

Slow or fast heartbeat and high blood pressure (US post-marketing reports, no rates)

Tell the clinician about palpitations, chest discomfort or a pounding headache.

Swollen legs or feet and rash (US post-marketing reports, no rates)

Usually checked by the team running the test; swelling of the face or throat is an allergy sign.

Steroid-type effects with repeated Synacthen Depot treatment: fluid retention, high blood sugar and blood pressure, mood changes (UK label)

Unlikely after a single test dose, the UK label says; they matter with repeated treatment.

Stop and get medical help

Hives, flushing, faintness, wheezing or trouble breathing after the injection: tell the staff at once, since most reactions start within 30 minutes (UK label).

Can it cause …?

The side effects people ask about most, answered one by one. Each answer says where it comes from.

Tiredness: LabelMalaise can be part of an allergic reaction (UK labels). Muscle weakness is listed only with repeated Synacthen Depot treatment.
Headache: LabelHeadache is listed with repeated Synacthen Depot treatment (UK label, frequency unknown); it isn’t listed after the single US test dose.
Nausea or vomiting: LabelNausea and vomiting can be signs of an allergic reaction (UK labels); they aren’t listed as a separate effect of the test dose.
Diarrhea or constipation: LabelNot listed after a single test. With repeated depot treatment, the UK label lists steroid-type effects such as peptic ulcer, pancreatitis and bloating.
Dizziness: LabelDizziness can come with an allergic reaction, and the UK labels warn against driving if it happens.
Trouble sleeping: LabelThe UK labels say the rise in adrenal steroids can trigger insomnia, mood swings or euphoria, mainly with repeated use.
Hair loss: LabelHair loss isn’t listed. Excess hair growth (hirsutism) is listed with repeated Synacthen Depot treatment.
Acne, rash or skin changes: LabelRash is in US post-marketing reports; hives, itching and flushing are allergy signs. Acne, thin skin, bruising and darker skin are listed with repeated depot use.
Water retention or swelling: LabelLeg and foot swelling is in US post-marketing reports; fluid and salt retention with repeated depot use. Swelling of the face or throat signals allergy.
Joint or muscle pain: LabelNot listed after a single test. Repeated depot use can cause steroid-type muscle weakness and wasting, bone thinning and tendon rupture (UK label).
Anxiety, low mood or irritability: LabelUK labels: raised adrenal steroids can trigger mood swings, euphoria, depression or psychosis and worsen existing mental illness; acute psychosis rules it out.
Low or high blood sugar: LabelUK labels: the extra steroids can raise blood sugar and unmask diabetes, mainly with repeated depot use; diabetes treatment may need adjusting.
Fast heartbeat or blood pressure changes: LabelSlow or fast heartbeat and high blood pressure are in US post-marketing reports, without rates. Heart failure is listed with repeated depot use.
More hunger: LabelIncreased appetite and weight gain are listed with repeated Synacthen Depot treatment (UK label); they aren’t expected after a single test dose.
Liver strain: LabelSevere jaundice was seen in children also taking valproate, and other seizure drugs may add liver risk (UK labels). Not otherwise listed.
Kidney problems: LabelNot listed as a side effect. UK labels urge weighing risks in kidney failure, and repeated depot use can lower potassium.
Cancer risk: LabelThe US label says no cancer studies were done in animals, and none of the labels list cancer as a risk.

Label: from the prescribing information. A side effect that hasn’t been reported can still happen, especially with long or high-dose use. Any of these across every compound: the side-effect finder.

Who should avoid it

What its label rules out or warns about, most important first.

Allergy to cosyntropin or ACTH: LabelRuled out by the labels; anaphylaxis has been reported. UK labels also rule it out in asthma or other allergies, where reactions tend to be more severe.
People taking steroids, spironolactone or estrogen: LabelA testing problem, not a safety one: these distort cortisol results, so the US label says to stop them on the test day, or 4–6 weeks earlier for estrogen.
Cirrhosis or nephrotic syndrome: LabelBoth can lower cortisol-binding globulin, the protein that carries cortisol, and make total cortisol read falsely low; the US label suggests measuring it.
Psychosis, peptic ulcer, infection or severe heart failure: LabelRuled out by the UK labels, because the rise in adrenal steroids can worsen them; Cushing’s syndrome is also on the list.
Pregnancy or breastfeeding: LabelCase reports over decades show no rise in birth defects or miscarriage, and the US label says suspected adrenal insufficiency in pregnancy shouldn’t go untested. No breast milk data exist.

Interactions

Only interactions stated on a product label or measured in a human study are listed.

Steroid medicines (such as prednisone or hydrocortisone) and spironolactone: LabelThey can falsely raise cortisol results; the US label says to stop them on the test day, and long-acting steroids earlier.
Estrogen-containing drugs (birth control pills, hormone therapy): LabelThey raise cortisol-binding globulin and total cortisol, so the label says to stop them 4–6 weeks before testing or to measure the binding protein.
Valproate and other seizure drugs (phenytoin, clonazepam, phenobarbital): LabelUK labels: severe jaundice occurred in children also given valproate, so the combination is to be avoided; other seizure drugs may add to liver risk.
Diabetes and blood pressure medicines: LabelWith repeated use, the extra steroids it releases can raise blood sugar and blood pressure, so UK labels say these treatments may need adjusting.

Label: a product label rules it out, warns about it or lists the interaction. This isn’t a complete list: a pharmacist or doctor can check a specific medicine or condition. Every documented interaction, by medicine: drug interactions.

Special situations

What the label and studies say about pregnancy, breastfeeding, kidney and liver problems, age and surgery.

Pregnancy: LabelCase reports over decades haven’t shown more birth defects or miscarriage. Undiagnosed adrenal insufficiency can harm mother and baby, so the US label says testing shouldn’t be delayed.
Breastfeeding: LabelNo data on breast milk. The US label says to weigh breastfeeding against the need for the test, and the UK label urges caution.
Kidney problems: LabelThe labels give no dose change. Nephrotic syndrome can lower cortisol-binding protein and skew results (US label), and UK labels say to weigh the risks in kidney failure.
Liver problems: LabelCirrhosis can lower cortisol-binding protein and make total cortisol read falsely low; the US label suggests measuring the binding protein.
Older adults: LabelUK labels: no evidence that the dose should differ in older people.
Children and teens: LabelApproved for the adrenal test from birth to 17 (US); Vial Guide doesn’t show children’s doses. Australia’s Synacthen Depot is also licensed for infantile spasms.
Surgery and anesthesia: LabelNo advice for a single test. After repeated depot treatment, the UK label warns the body’s own stress response may fail after surgery or injury; tell the surgical team.

Label: what the prescribing information says. Ages are given as approved or studied; this site never gives doses for children. Across every compound: pregnancy, breastfeeding, kidney disease, liver disease, older adults and surgery.

Tracking and pairing

Worth tracking

Cortisol at baseline, 30 and 60 minutes (label)
Cortisol-binding globulin if on estrogen or with cirrhosis or nephrotic syndrome (label)
Signs of allergy for 30 minutes after the injection (UK label)
Blood pressure and blood sugar during repeated depot treatment (UK label)

Often paired with

Usually run on its own.

Human studies

5 key published human studies, with how many people took part. Animal studies aren’t listed here.

20161,537 people

Both tests had similar accuracy for pituitary-related adrenal insufficiency (35 studies in all): good at ruling it in, poor at ruling it out. The standard test caught 92% of primary adrenal insufficiency.

Design
Systematic review and meta-analysis of diagnostic accuracy studies
Dose
250 mcg (standard) vs 1 mcg (low-dose) tests
Length
Single tests

Ospina et al., J Clin Endocrinol Metab 2016, PMID 26649617
2021110 people

With the old 18 mcg/dL cutoff, 14.5% to 32% of patients were labeled abnormal depending on the assay; the equivalent cutoff on newer assays was 14.5–14.8 mcg/dL at 30 minutes.

Design
Retrospective study of ACTH stimulation tests run in parallel on older and newer cortisol assays
Dose
Standard cosyntropin test
Length
Single tests

Javorsky et al., J Endocr Soc 2021, PMID 33768189
2004107 people

Spasms stopped on days 13–14 in 73% on hormone treatment (76% with tetracosactide) vs 54% on vigabatrin.

Design
Randomized controlled trial in infants with infantile spasms (UKISS)
Dose
Hormone treatment (tetracosactide depot or prednisolone) vs vigabatrin; Vial Guide doesn’t show children’s doses
Length
14 days to the main outcome

Lux et al., Lancet 2004, PMID 15541450
201090 people

Post-puncture headache in 33% vs 69% on saline, and fewer blood patches (11% vs 29%); headaches that did occur were no milder or shorter.

Design
Randomized controlled trial in women after an accidental dural puncture during a labor epidural
Dose
1 mg IV once after delivery, vs saline
Length
Single dose

Hakim, Anesthesiology 2010, PMID 20613476
202544 people

An epidural blood patch was still needed by 91% vs 86% on placebo; hospital stays were 1 day longer on tetracosactide.

Design
Randomized double-blind placebo-controlled trial in women with headache after spinal or epidural anesthesia for childbirth, stopped early for futility
Dose
Tetracosactide 1 mg IV once, vs placebo
Length
15 days of follow-up

Dziadzko et al., Br J Anaesth 2025, PMID 40393818

All human studies on Vial Guide

Trials under way

Registered trials that are still running, or that finished without published results, most important first. Checked on ClinicalTrials.gov, October 7, 2026.

Not applicableNCT05149638
Cosyntropin tests in 90 people with suspected adrenal insufficiency, to reset the cortisol cutoff for a newer, more specific assay
Recruiting since February 2022; completion expected December 2027
Phase 2NCT03514589
NeSST2: nasal tetracosactide vs IV in 12 participants, to develop a needle-free short Synacthen test
Listed as recruiting, but its estimated December 2025 completion has passed; no results posted
ObservationalNCT07866326
Morning cortisol and Synacthen tests in 120 people with rheumatoid arthritis on low-dose steroids: how common adrenal insufficiency is
Recruiting since July 2026; completion expected July 2027
Not applicableNCT03793114
Cosyntropin tests in 200 people with Addison’s disease: how many still make some cortisol and aldosterone
Active, not recruiting; completion expected December 2029

Every compound’s registered trials: trials under way.

Limits of the evidence

Cosyntropin is approved as a test, and its labels rest on decades of clinical use rather than modern trials; side effects come from post-marketing reports without rates. How well the test performs depends on cutoffs and assays that differ between labs, and meta-analyses rate that evidence low to moderate. Treatment uses of the depot abroad, and off-label uses such as preventing headache after spinal puncture, rest on small or conflicting trials.

How it’s supplied

Single-dose vials of 0.25 mg powder, mixed with 1 mL of saline (US); abroad, 250 mcg/mL ampoules (Synacthen) and a 1 mg/mL slow-release suspension (Synacthen Depot). Injected once into a vein or muscle by a clinician, with blood drawn for cortisol before and after. The depot goes into a muscle only, never a vein. It’s used as supplied, so the calculator and dose log don’t apply.

The US powder is mixed with 1 mL of 0.9% sodium chloride (0.25 mg/mL) and used right away; any leftover is discarded. The whole vial is the adult test dose.

Datasheet

Half-life: about 7 minutes, with a 3-hour tail LabelAfter an IV injection, plasma levels fall in three phases: half-lives of about 7 minutes in the first hour, 37 minutes in the second and 3 hours after that. Synacthen Depot keeps levels up for about 12 hours.
Type: Peptide, 24 amino acids
Molecular weight: 2,933.4 g/mol
Formula: C₁₃₆H₂₁₀N₄₀O₃₁S
Sequence: SYSMEHFRWGKPVGKKRRPVKVYPResidues 1–24 of human ACTH
Storage before use: US vials of powder: 20–25 °C (excursions 15–30 °C allowed). Synacthen ampoules and Synacthen Depot: fridge (2–8 °C), protected from light.
After mixing or opening: Mixed US solution is used right away and any leftover discarded; it has no preservative. The depot ampoule is shaken before use.

Half-life: Synacthen UK SmPC, section 5.2 (Atnahs, rev. November 2024); Synacthen Depot UK SmPC, section 5.2 (rev. April 2025)
Molecule: Cortrosyn label rev. 01/2025, section 11 (formula; MW given as 2934); PubChem CID 16129617; FDA GSRS, UNII 72YY86EA29 (sequence). UK products use the acetate.
Storage: Label Cortrosyn prescribing information (January 2025), sections 2.4 and 16; Synacthen and Synacthen Depot UK SmPCs, sections 6.4 and 6.6

Every compound side by side: the half-life chart and the storage chart.

Identifiers

CAS number: 16960-16-0
UNII (FDA): 72YY86EA29
PubChem CID: 16129617
DrugBank: DB01284
ATC code: H01AA02
Brand names: Cortrosyn (US, Canada), Synacthen (UK, Australia, Europe, Synacthène in France), Synacthen Depot (UK, Australia; dormant in Canada); generic cosyntropin (US)
First described: Full-length ACTH was first synthesized in 1963 (Schwyzer and Sieber). First US approval: Cortrosyn, April 22, 1970.

Every compound’s numbers: the identifiers table.

Product form and quality

Cosyntropin and tetracosactide are the same peptide, ACTH 1–24; UK products use the acetate. Synacthen Depot binds it to zinc phosphate for slow release, so it isn’t interchangeable with the short-acting test vials and ampoules.

Cautions

Allergic reactions, including anaphylaxis, have been reported. They tend to start within 30 minutes, so the UK label says to keep patients under observation for that time.
Results can mislead: steroid medicines and spironolactone falsely raise cortisol, and estrogen (including birth control pills) raises total cortisol, so the US label says to stop them before testing.
Cirrhosis or nephrotic syndrome can lower the protein that carries cortisol and skew results; the US label suggests measuring it.
UK labels rule it out in asthma or other allergies, acute psychosis, active infections, peptic ulcer, severe heart failure and Cushing’s syndrome.

Questions

What is cosyntropin?

The first 24 of the 39 amino acids of ACTH, the pituitary hormone that tells the adrenal glands to make cortisol. One injection shows whether the adrenal glands can respond by raising cortisol.

How does cosyntropin work?

Cosyntropin is the first 24 amino acids of ACTH (adrenocorticotropic hormone), the pituitary signal that drives the adrenal glands. It binds the ACTH receptor on adrenal cells, which then release cortisol and other steroid hormones within minutes; the standard test dose stimulates them as fully as natural ACTH does. A weak cortisol rise means the adrenal glands can’t respond normally. Lacking the end of ACTH that the immune system recognizes most, it rarely triggers antibodies. Both the standard and low-dose tests can miss pituitary-related adrenal insufficiency, and the right cortisol cutoff depends on the lab’s assay. Effects of repeated depot treatment are mostly known from steroid-type side effects, not trials.

Is cosyntropin FDA-approved?

Approved in the US as Cortrosyn (since 1970) and generic cosyntropin, as a diagnostic test for adrenal insufficiency in adults and children. No US cosyntropin product is approved for treatment, and Synacthen Depot isn’t sold in the US.

What is the usual cosyntropin dose?

From the label (Cortrosyn and generics): Adults: 0.25 mg once, into a vein or muscle. Cortisol is measured just before and exactly 30 and 60 minutes after; a level under 18 mcg/dL at either time suggests adrenal insufficiency. Adults: 1 mg into a muscle, with cortisol measured over 5 hours, when the short test is unclear; a 3-day version separates adrenal from pituitary causes (Synacthen Depot (UK)). These are the amounts sources reference, not recommendations.

How is cosyntropin given?

Injected once into a vein or muscle by a clinician, with blood drawn for cortisol before and after. The depot goes into a muscle only, never a vein. The US label says to stop steroid medicines and spironolactone on the test day (long-acting steroids earlier) and estrogen-containing drugs 4–6 weeks before.

Who should avoid cosyntropin?

Allergy to cosyntropin or ACTH: Ruled out by the labels; anaphylaxis has been reported. UK labels also rule it out in asthma or other allergies, where reactions tend to be more severe. People taking steroids, spironolactone or estrogen: A testing problem, not a safety one: these distort cortisol results, so the US label says to stop them on the test day, or 4–6 weeks earlier for estrogen. Cirrhosis or nephrotic syndrome: Both can lower cortisol-binding globulin, the protein that carries cortisol, and make total cortisol read falsely low; the US label suggests measuring it. The “Who should avoid it” section lists 2 more groups and 4 interactions.

What is the half-life of cosyntropin?

About 7 minutes, with a 3-hour tail, according to the prescribing information. After an IV injection, plasma levels fall in three phases: half-lives of about 7 minutes in the first hour, 37 minutes in the second and 3 hours after that. Synacthen Depot keeps levels up for about 12 hours.

How should cosyntropin be stored?

US vials of powder: 20–25 °C (excursions 15–30 °C allowed). Synacthen ampoules and Synacthen Depot: fridge (2–8 °C), protected from light. Mixed US solution is used right away and any leftover discarded; it has no preservative. The depot ampoule is shaken before use.

Is cosyntropin banned in sport?

Yes. S2.2.2 corticotrophins and their releasing factors, with tetracosactide named. Banned at all times.

Has cosyntropin been studied in people?

Yes. The human studies section lists 5 published studies. The largest, from 2016, included 1,537 people. Both tests had similar accuracy for pituitary-related adrenal insufficiency (35 studies in all): good at ruling it in, poor at ruling it out. The standard test caught 92% of primary adrenal insufficiency.

How long has cosyntropin been studied in people?

Label Mostly single test doses. Synacthen Depot is licensed only for short-term treatment, and no study of long-term use was found.

Does cosyntropin come in other forms, like a pill or nasal spray?

Label Given into a vein or a muscle; Synacthen Depot into a muscle only. A small UK trial is testing a needle-free nasal version of the short test; no nasal or oral form is approved.

Can you drink alcohol while taking cosyntropin?

No study The labels don’t mention alcohol, and no study has tested the combination.

Can cosyntropin be taken with semaglutide or tirzepatide?

No study No study has combined them, and neither drug’s label lists an interaction.

What happens if you take too much cosyntropin?

Label As a single test dose, overdose is unlikely (UK label). Repeated depot doses that are too high can cause fluid retention and Cushing’s-type effects. Call Poison Help (1-800-222-1222), or emergency services for severe symptoms.

Sources

Cortrosyn (cosyntropin) for injection prescribing information, Amphastar (DailyMed, January 30, 2025)
Cosyntropin for injection prescribing information, Sandoz (DailyMed, January 10, 2024)
Drugs@FDA: Cortrosyn NDA 016750 (approved April 22, 1970); cosyntropin solution NDA 022028 (February 21, 2008, discontinued); generic powders ANDA 090574 (December 17, 2009) and ANDA 202147 (June 29, 2012)
Synacthen Ampoules 250 micrograms and Synacthen Depot Ampoules 1 mg/ml, UK summaries of product characteristics (Atnahs Pharma, rev. November 27, 2024 and April 29, 2025)
Synacthen and Synacthen Depot Australian product information (Atnahs Pharma Australia, rev. March 2020)
Ospina et al., ACTH stimulation tests for diagnosing adrenal insufficiency, systematic review and meta-analysis (J Clin Endocrinol Metab 2016) PMID 26649617

For the protocol details

Cortrosyn prescribing information, sections 2, 4, 5, 6 and 7 (Amphastar, DailyMed, January 30, 2025)
Synacthen and Synacthen Depot UK summaries of product characteristics, sections 4.1–4.8 (Atnahs Pharma, 2024 and 2025)
Javorsky et al., new cortisol cutoffs after ACTH stimulation with specific assays (J Endocr Soc 2021) PMID 33768189

For how it works, who should avoid it and the limits of the evidence

Cortrosyn prescribing information, sections 2, 4, 5, 7, 8 and 12 (Amphastar, DailyMed, January 30, 2025)
Synacthen Ampoules 250 micrograms, UK summary of product characteristics, sections 4.3–4.8 (Atnahs Pharma, rev. November 27, 2024)
Synacthen Depot Ampoules 1 mg/ml, UK summary of product characteristics, sections 4.3–4.8 (Atnahs Pharma, rev. April 29, 2025)
Dziadzko et al., tetracosactide for postdural puncture headache after childbirth (Br J Anaesth 2025) PMID 40393818

For uses, the side-effect questions, special situations, trials, identifiers and status outside the US

Cortrosyn (cosyntropin) for injection prescribing information, sections 1, 2, 5, 6, 8 and 13 (Amphastar, DailyMed, January 30, 2025)
Synacthen Ampoules 250 micrograms and Synacthen Depot Ampoules 1 mg/ml, UK summaries of product characteristics (Atnahs Pharma, PL 43252/0026 and 0027, rev. November 27, 2024 and April 29, 2025)
Synacthen and Synacthen Depot Australian product information, Schedule 4 (Atnahs Pharma Australia, rev. March 17 and 18, 2020)
Health Canada Drug Product Database entries for Cortrosyn and Synacthen Depot (checked October 8, 2026)
French medicines database (BDPM) entries for Synacthène and Synacthène Retard (data file of October 2026)
Drugs@FDA: Cortrosyn NDA 016750, original approval April 22, 1970
Lux et al., UKISS trial of hormone treatment vs vigabatrin for infantile spasms (Lancet 2004) PMID 15541450
Hakim, cosyntropin to prevent postdural puncture headache (Anesthesiology 2010) PMID 20613476
Schwyzer and Sieber, total synthesis of adrenocorticotrophic hormone (Nature 1963) PMID 14043189
WADA 2026 Prohibited List, section S2.2.2
FDA Global Substance Registration System record (UNII 72YY86EA29) and PubChem CID 16129617
ClinicalTrials.gov registry entries for the trials listed (checked October 8, 2026)

By Vial Guide editorsLast reviewed October 7, 2026

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