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 51500-7: E2 7th specimen post Unsp challenge [Mass/Vol]

Name: LOINC Code 51500-7: E2 7th specimen post Unsp challenge [Mass/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:35.012Z

51500-7 is a LOINC code used to identify E2 7th specimen post Unsp challenge [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 Estradiol^7th specimen post XXX challenge. 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 Estradiol^7th specimen post XXX challenge. 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

Estradiol (E2) [Mass/volume] in Serum or Plasma --7th specimen post XXX challenge
Estradiol^7th specimen post XXX challenge
^7th spec pst XXX chal; 17-beta estradiol; After; CHEMISTRY.CHALLENGE TESTING; E2; Level; Mass concentration; Oestradiol; p chal; Pl; Plasma; Plsm; Point in time; PST; QNT; Quan; Quant; Quantitative; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; sp7; sp7 p chal; Spec; SR

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

E2 7th specimen post Unsp challenge [Mass/Vol]Estradiol (E2) [Mass/volume] in Serum or Plasma --7th specimen post XXX challengeEstradiol sp7 p chal SerPl-mCncEstradiol^7th specimen post XXX challengeCHALEstradiol 7th specimen after challenge, BloodMCnc

Frequently asked questions

Code details

Code51500-7

SystemLOINC

Display nameE2 7th specimen post Unsp challenge [Mass/Vol]

DescriptionEstradiol^7th specimen post XXX challenge

Short nameEstradiol sp7 p chal SerPl-mCnc

ComponentEstradiol^7th specimen post XXX challenge

PropertyMCnc

TimingPt

System (specimen)Ser/Plas

ScaleQn

ClassCHAL

Example unitspg/mL

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.24

Last changed2.70

Consumer names

Estradiol 7th specimen after challenge, Blood

Part names

Estradiol^7th specimen post XXX challengeMCncPtSer/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.