Our global life sciences company brings diagnostic testing & drug development together.

Cortisol (Dexamethasone Suppression Test) With Reflex to Dexamethasone

CPT: 82533
Print Share


  • Dexamethasone Suppression Test

Test Includes

If the cortisol (503990) result is >1.7 μg/dL, dexamethasone test will be performed. Adequate dexamethasone drug level is confirmed with dexamethasone reflex measurement.

Special Instructions

For more information regarding the administration and interpretation of the dexamethasone suppression test (DST) in the evaluation of patients for Cushing disease/syndrome, please see Dexamethasone Suppression Screening for Cushing Disease/Syndrome in the online Endocrine Appendix.

Expected Turnaround Time

6 - 15 days

Related Documents

Specimen Requirements


Serum or plasma, frozen


3 mL

Minimum Volume

1 mL (Note: This volume does not allow for repeat testing.)


Red-top tube, gel-barrier tube, lavender-top (EDTA) tube, or green-top (heparin) tube


Specimen must be separated from cells within one hour of venipuncture. Transfer serum or plasma to a plastic transport tube and freeze. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.

Storage Instructions


Stability Requirements



Room temperature

2 days


2 days


1 year

Freeze/thaw cycles

Stable x3

Causes for Rejection

Gross hemolysis

Test Details


A reflex profile that tests adrenal suppression with dexamethasone.


False-positive results can be seen in obese individuals, in those who have had a poor night's sleep, and in individuals who are under acute emotional or physical stress.


High-pressure liquid chromatography (HPLC)/tandem mass spectrometry (MS-MS)

Reference Interval

Positive: Serum cortisol >1.7 μg/dL after single-dose dexamethasone


Magiakou MA, Mastorakos G, Oldfield EH, et al. Cushing's syndrome in children and adolescents. Presentation, diagnosis, and therapy. N Engl J Med. 1994 Sep 8; 331(10):629-636. 8052272


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
503990 Cortisol Dexamethasone Reflex 500155 Cortisol, Serum LCMS ug/dL 2143-6
503990 Cortisol Dexamethasone Reflex 503991 Dexamethasone Reflex n/a
Reflex Table for Dexamethasone Reflex
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 500118 Dexamethasone, Serum 500119 Dexamethasone, Serum ng/dL 14062-4
Reflex Table for Dexamethasone Reflex
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 500118 Dexamethasone, Serum 500980 Dexamethasone, Serum n/a

For Providers

Please login to order a test

Order a Test

© 2021 Laboratory Corporation of America® Holdings and Lexi-Comp Inc. All Rights Reserved.

CPT Statement/Profile Statement

The LOINC® codes are copyright © 1994-2021, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee. Permission is granted in perpetuity, without payment of license fees or royalties, to use, copy, or distribute the LOINC® codes for any commercial or non-commercial purpose, subject to the terms under the license agreement found at Additional information regarding LOINC® codes can be found at, including the LOINC Manual, which can be downloaded at