Synacthen Stimulation Test (Blood)

Department

Chemical Pathology

Delphic Registration Code (Alpha Code)

MCOR

Test Code (Numeric Code)

0377

Laboratory Handling

Sample Stability

4 days 2-8 °C

Associated Tests

Synonyms

Basal Synacthen
Post Synacthen (30mins)
Post Synacthen (60mins)

Turnaround Time

4 hours

Available 24 hours

Specimen Type

  • Plasma
  • Serum

Specimen Requirements

Tube/Container Type:

Preferred
  • Lithium Heparin - Non-gel (Green Cap)
Acceptable
  • Plain (Red Top)
Preferred Sample Volume (ml)

4

Paediatric Specimen Requirements

Tube/Container Type:

Preferred
  • Heparin (Microtainer)
Acceptable
  • Plain(Microtainer)
Minimum Sample Volume (ml)

0.4

Pre-testing Requirements

Specifying the collection times for basal and post-synacthen is essential (see below)

Additional Specimen Information

If the patient is an inpatient at MMH - it is expected that the team performs the synacthen test themselves in the ward. Tetracosactrin ("Synacthen") can be ordered through the pharmacy department.

For CMH outpatients only: As medical staff from the Biochemistry laboratory have to be present to administer the tetracosactrin, it is NECESSARY that the patient or the team rings Middlemore Hospital laboratory blood collection room ((09) 276 0044 extension 58503) to make an appointment prior to the patient's discharge. If a patient turns up with a form to the blood collection room without prior arrangement - the request will be declined.

Sample 1 (If basal level is required) 4.5 mL blood in heparin (preferred) or plain tube. Request "Basal Synacthen cortisol" on the form and state collection time. Label specimen with the collection time and as "Basal". If a basal ACTH is also required, will need a separate 4.5mls EDTA blood collect. Then give 0.25mg Synacthen IV or IM.

Sample 2 (30 mins. or 60mins. after administration) 4.5 mL blood - heparin preferred or 6 mL plain tube. Please request "Post Synacthen Cortisol" on the form and also state the exact time interval post dose (30mins or 60mins). Label specimen with collection time and as "Post Synacthen". Send separately to the laboratory.

If the stimulation test is for diagnosis of congenital adrenal hyperplasia, other tests including 17-OHP or adrenal androgens (baseline and post-stimulation) may also be included - follow local endocrinology team protocol.

Last updated: 17/06/2026