What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveObservation

LOINC Code 77939-7: Corticotropin 45 Min post Unsp challenge (P) [Moles/Vol]

Name: LOINC Code 77939-7: Corticotropin 45 Min post Unsp challenge (P) [Moles/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:58.755Z

77939-7 is a LOINC code used to identify Corticotropin 45 Min post Unsp challenge (P) [Moles/Vol] in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Corticotropin^45M post XXX challenge. It is commonly used with the system or sample type Plas.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Corticotropin^45M post XXX challenge. It is commonly used with the system or sample type Plas.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: ACTIVE
Order vs observation: Observation

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Corticotropin [Moles/volume] in Plasma --45 minutes post XXX challenge
Corticotropin^45M post XXX challenge
Timed specimens are measured for corticotropin (also called adrenocorticotropic hormone or ACTH) for adrenocorticotropic hormone challenge tests to assist in diagnosing adrenocortical insufficiency as found in Cushing's syndrome and Addison's disease. For the CRH (corticotropin-releasing hormone) stimulation, CRH is given and cortisol and ACTH levels are determined before the injection, at the injection time, and specified times following injection. The CRH stimulation test is used to distinguish Cushings disease from conditions where ACTH is secreted ectopically. For the Metyrapone (overnight) stimulation challenge, metyrapone is given with a snack at midnight. Samples for cortisol, 11-deoxycortisol, and ACTH are collected the following morning. The metyrapone stimulation test distinguishes corticotropin-dependent causes (pituitary Cushing's disease and ectopic Cushing's disease) from corticotropin-independent causes (carcinoma of the lung or thyroid).
45M p chal; ACTH; Adrenocorticotrophic hormone; Adrenocorticotropin; After; c206; c74; CHEMISTRY.CHALLENGE TESTING; Cortrosyn; Level; p chal; Pl; Plasma; Plsm; Point in time; PST; QNT; Quan; Quant; Quantitative; Random; Rc206; Substance concentration; Tumor marker

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Corticotropin 45 Min post Unsp challenge (P) [Moles/Vol]Corticotropin [Moles/volume] in Plasma --45 minutes post XXX challengeACTH 45M p chal Plas-sCncCorticotropin^45M post XXX challengeCHALCorticotropin 45 min after challenge, BloodSCnc

Frequently asked questions

Code details

Code77939-7

SystemLOINC

Display nameCorticotropin 45 Min post Unsp challenge (P) [Moles/Vol]

DescriptionCorticotropin^45M post XXX challenge

Short nameACTH 45M p chal Plas-sCnc

ComponentCorticotropin^45M post XXX challenge

PropertySCnc

TimingPt

System (specimen)Plas

ScaleQn

ClassCHAL

Example unitspmol/L

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.52

Last changed2.58

Consumer names

Corticotropin 45 min after challenge, Blood

Part names

Corticotropin^45M post XXX challengeSCncPtPlasQnSubstance ConcentrationPoint in time (spot)Plasma

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.