> ## Documentation Index
> Fetch the complete documentation index at: https://docs.metriport.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Substance

> A homogeneous material with a definite composition.

## Properties

| Name | Required | Type | Description |
| - | - | - | - |
| identifier | No | [Identifier](/medical-api/fhir/data-types/identifier)\[] | Unique identifier |
| status | No | code | active / inactive / entered-in-error |
| category | No | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept)\[] | What class/type of substance this is |
| code | Yes | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept) | What substance this is |
| description | No | string | Textual description of the substance, comments |
| instance | No | SubstanceInstance | If this describes a specific package/container of the substance |
| - id | No | string | Unique id for inter-element referencing |
| - extension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Additional content defined by implementations |
| - modifierExtension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Extensions that cannot be ignored even if unrecognized |
| - identifier | No | [Identifier](/medical-api/fhir/data-types/identifier) | Identifier of the package/container |
| - expiry | No | dateTime | When no longer valid to use |
| - quantity | No | [Quantity](/medical-api/fhir/data-types/quantity) | Amount of substance in the package |
| ingredient | No | SubstanceIngredient | Composition information about the substance |
| - id | No | string | Unique id for inter-element referencing |
| - extension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Additional content defined by implementations |
| - modifierExtension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Extensions that cannot be ignored even if unrecognized |
| - quantity | No | [Ratio](/medical-api/fhir/data-types/ratio) | Optional amount (concentration) |
| - substance\[x] | Yes | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept), Reference\<[Substance](/medical-api/fhir/resources/substance)> | A component of the substance |

## Search Parameters

| Name | Type | Description | Expression |
| - | - | - | - |
| category | token | The category of the substance | Substance.category |
| code | token | The code of the substance or ingredient | Substance.code |
| container-identifier | token | Identifier of the package/container | Substance.instance.identifier |
| expiry | date | Expiry date of package or container of substance | Substance.instance.expiry |
| identifier | token | Unique identifier for the substance | Substance.identifier |
| quantity | quantity | Amount of substance in the package | Substance.instance.quantity |
| status | token | active / inactive / entered-in-error | Substance.status |
| substance-reference | reference | A component of the substance | Substance.ingredient.substance |

## Inherited Properties

| Name | Required | Type | Description |
| - | - | - | - |
| id | No | string | Logical id of this artifact |
| meta | No | [Meta](/medical-api/fhir/data-types/meta) | Metadata about the resource |
| implicitRules | No | uri | A set of rules under which this content was created |
| language | No | code | Language of the resource content |
| text | No | [Narrative](/medical-api/fhir/data-types/narrative) | Text summary of the resource, for human interpretation |
| contained | No | Resource\[] | Contained, inline Resources |
| extension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Additional content defined by implementations |
| modifierExtension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Extensions that cannot be ignored |

To view the FHIR specification for this resource, see [Substance](https://www.hl7.org/fhir/StructureDefinition/Substance).


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.