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 55509-4: Somatotropin 45 Min post dose cloNIDine [Mass/Vol]

Name: LOINC Code 55509-4: Somatotropin 45 Min post dose cloNIDine [Mass/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:37.765Z

55509-4 is a LOINC code used to identify Somatotropin 45 Min post dose cloNIDine [Mass/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 Somatotropin^45M post dose cloNIDine. It is commonly used with the system or sample type Ser/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 Somatotropin^45M post dose cloNIDine. It is commonly used with the system or sample type Ser/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

Somatotropin [Mass/volume] in Serum or Plasma --45 minutes post dose cloNIDine
Somatotropin^45M post dose cloNIDine
45M p CLN; After; Catapres; CHEMISTRY.CHALLENGE TESTING; Endocrine; Endocrinology; GH; Growth hormone; HGH; Human growth hormone; Level; Mass concentration; p dose; Pl; Plasma; Plsm; Point in time; PST; QNT; Quan; Quant; Quantitative; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; Somatotropic hormone; SR; STH

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

Somatotropin 45 Min post dose cloNIDine [Mass/Vol]Somatotropin [Mass/volume] in Serum or Plasma --45 minutes post dose cloNIDineGH 45M p CLN SerPl-mCncSomatotropin^45M post dose cloNIDineCHALSomatotropin 45 min after cloNIDine, BloodMCnc

Frequently asked questions

Code details

Code55509-4

SystemLOINC

Display nameSomatotropin 45 Min post dose cloNIDine [Mass/Vol]

DescriptionSomatotropin^45M post dose cloNIDine

Short nameGH 45M p CLN SerPl-mCnc

ComponentSomatotropin^45M post dose cloNIDine

PropertyMCnc

TimingPt

System (specimen)Ser/Plas

ScaleQn

ClassCHAL

Example unitsug/L;ng/mL

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.27

Last changed2.40

Consumer names

Somatotropin 45 min after cloNIDine, Blood

Part names

Somatotropin^45M post dose cloNIDineMCncPtSer/PlasQnMass ConcentrationPoint in time (spot)Serum or 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.