Preferred Sample Type

Adrenocorticotrophic Hormone (ACTH)

Suitable Specimen Types

EDTA Plasma

Adrenocorticotrophic Hormone (ACTH)

Specimen Volume

1 mL blood

Specimen Transport

The sample should be delivered to the lab on ice immediately after collection.

Sample Preparation

The sample should be collected into an EDTA tube (purple top) on ice.

Turnaround Time

14 days

Sample Processing In Laboratory

Time of collection should be noted, the sample should be centrifuged immediately upon receipt and the separated sample should be transferred to a labelled plastic tube and stored at -20°C within 30 minutes of sample collection.

Sample Stability

Store plasma immediately at -20°C

General Information

Adrenocorticotropic hormone (ACTH) is produced in the pituitary gland to stimulate secretion of cortisol by the adrenal glands. Normally, ACTH increases when cortisol is low and falls when cortisol is high. The concentration of ACTH varies greatly at different times of the day, with the highest amount at about 8 am and the lowest about midnight, therefore the sample will normally be collected first thing in the morning.

Secretion of ACTH may be increased by stress.

Some drugs and conditions can cause ACTH levels to rise, including amphetamines, insulin, levodopa, and metoclopramide.

Drugs that cause ACTH to fall include dexamethasone and other drugs that act like cortisol (including prednisone, hydrocortisone, prednisolone, and methylprednisolone), and megestrol acetate.

Ectopic tumours may secrete fragments or big ACTH which are biologically active but undetected by the assay.


ACTH samples are referred to Russell's Hall Hospital.

Patient Preparation

Ensure patient is not taking corticosteroids, synacthen and avoid undue stress. Please state time of collection. Lithium heparin interferes with the assay. Take blood into EDTA tubes and send to the lab immediately on ice.


To diagnose adrenal and pituitary diseases such as Cushing's syndrome, Cushing's disease, Addison's disease, adrenal tumors, and pituitary tumors; usually done as a diagnostic test once an abnormal cortisol level is detected.

Reference Range

Provided by referral laboratory

Source of Reference Range

Abbott Diagnostics


  • EQA Status: UK NEQAS
  • EQAS Scheme: Yes

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