CompositionComparison
Expresses that one substance has a similar biochemical composition to another, establishing the basis for biocompatibility, substitution, or therapeutic effectiveness. This type captures the "this works because it's similar to what your body makes" logic that underpins many natural and bioidentical treatments.
Properties
Properties from CompositionComparison (in addition to properties inherited from Intangible and Thing):
| Property | Expected Type | Description |
|---|---|---|
| name | Text | Name of the comparison (e.g., "Tallow-sebum fatty acid similarity") |
| substance | ChemicalSubstance or Product | The substance being evaluated for compositional similarity |
| comparedTo | ChemicalSubstance or AnatomicalStructure | The reference substance or endogenous material being compared to |
| sharedComponents | ChemicalSubstance | Specific components present in both substances |
| similarityBasis | Text | What aspect of composition is similar (e.g., "Fatty acid profile proportions") |
| similarityDegree | Text or QuantitativeValue | How similar (qualitative description or percentage match) |
| clinicalRelevance | Text | Why this compositional similarity matters therapeutically |
| limitations | Text | Important differences, caveats, or boundaries of the comparison |
| evidenceSource | Text, URL, or CreativeWork | Reference to evidence supporting this compositional comparison |
Examples
Example 1: Tallow and Human Sebum
The core compositional argument for tallow-based skincare:
JSON-LD
{
"@context": [
"https://schema.org",
{
"hs": "https://healthschema.org/",
"CompositionComparison": "hs:CompositionComparison"
}
],
"@type": "CompositionComparison",
"name": "Tallow-sebum fatty acid similarity",
"substance": {
"@type": "ChemicalSubstance",
"name": "Grass-fed beef tallow"
},
"comparedTo": {
"@type": "AnatomicalStructure",
"name": "Human sebum",
"description": "Protective oil produced by sebaceous glands"
},
"sharedComponents": [
{
"@type": "ChemicalSubstance",
"name": "Oleic acid",
"description": "37-47% in tallow; major component of sebum"
},
{
"@type": "ChemicalSubstance",
"name": "Palmitic acid",
"description": "26-28% in tallow; significant sebum component"
},
{
"@type": "ChemicalSubstance",
"name": "Stearic acid",
"description": "17-25% in tallow; present in sebum"
}
],
"similarityBasis": "Fatty acid profile proportions",
"clinicalRelevance": "May substitute for endogenous lipids in tissues lacking sebum production (e.g., lip vermilion), providing familiar molecular structures that integrate with the skin's lipid matrix",
"limitations": "Compositional similarity does not guarantee equivalent function; limited clinical trials specifically comparing tallow to other emollients; individual response varies"
}Example 2: Jojoba Oil and Sebum
A plant-based composition comparison:
JSON-LD
{
"@context": [
"https://schema.org",
{
"hs": "https://healthschema.org/",
"CompositionComparison": "hs:CompositionComparison"
}
],
"@type": "CompositionComparison",
"name": "Jojoba oil-sebum wax ester similarity",
"substance": {
"@type": "ChemicalSubstance",
"name": "Jojoba oil"
},
"comparedTo": {
"@type": "AnatomicalStructure",
"name": "Human sebum"
},
"sharedComponents": [
{
"@type": "ChemicalSubstance",
"name": "Wax esters",
"description": "Jojoba is technically a liquid wax, not an oil; sebum contains 25-30% wax esters"
}
],
"similarityBasis": "Wax ester structure (unique among plant oils)",
"similarityDegree": "Closest plant-derived match to sebum's wax ester component",
"clinicalRelevance": "The wax ester composition allows jojoba to integrate with skin's natural lipid barrier more readily than triglyceride-based plant oils",
"limitations": "Sebum is more complex than jojoba alone; does not contain the full range of sebum's fatty acid diversity"
}Example 3: Bioidentical Hormone Comparison
Molecular structure comparison for hormone therapy:
JSON-LD
{
"@context": [
"https://schema.org",
{
"hs": "https://healthschema.org/",
"CompositionComparison": "hs:CompositionComparison"
}
],
"@type": "CompositionComparison",
"name": "Bioidentical estradiol molecular identity",
"substance": {
"@type": "ChemicalSubstance",
"name": "Bioidentical 17β-estradiol",
"description": "Plant-derived estradiol used in hormone therapy"
},
"comparedTo": {
"@type": "ChemicalSubstance",
"name": "Endogenous 17β-estradiol",
"description": "Estradiol produced by human ovaries"
},
"similarityBasis": "Identical molecular structure",
"similarityDegree": {
"@type": "QuantitativeValue",
"value": 100,
"unitText": "percent molecular identity"
},
"clinicalRelevance": "Identical molecular structure means identical receptor binding and metabolic pathways; the body cannot distinguish bioidentical from endogenous hormones",
"limitations": "Bioidentical does not mean risk-free; delivery method and dosing still affect outcomes; not all 'natural' hormones are bioidentical"
}Usage Notes
When to Use CompositionComparison
Use CompositionComparison when your content explains:
- Biocompatibility rationales — Why a substance is compatible with human tissue based on composition
- Natural alternatives — How natural products compare to synthetic or endogenous substances
- Substitution logic — Why one substance can substitute for another
- Bioidentical claims — The compositional basis for bioidentical products
- Ingredient selection rationale — Why specific ingredients are chosen for formulations
Why CompositionComparison Exists
Schema.org Gap
Schema.org can describe substances individually but cannot express compositional relationships between them:
- ChemicalSubstance — Describes a substance but not how it relates to others compositionally
- sameAs — Implies identity, not similarity
- hasBioChemEntityPart — Lists components but doesn't compare to reference substances
CompositionComparison fills this gap by formally expressing "substance A resembles substance B because of shared components C, D, E" — essential for explaining why natural or bioidentical treatments work.
Best Practices
- Be specific about components — List the actual shared components rather than vague "similar composition" claims
- State the basis — Clarify what aspect of composition is being compared (fatty acids, amino acids, molecular structure)
- Acknowledge limitations — Use the
limitationsproperty to maintain scientific honesty about what the comparison does and doesn't prove - Quantify when possible — Use
similarityDegreewith specific percentages or QuantitativeValue when data supports it - Explain relevance — The
clinicalRelevanceproperty should connect compositional similarity to practical outcomes - Avoid overclaiming — Compositional similarity is necessary but not sufficient evidence for equivalent therapeutic effect
Related Types
Health Schema Types
Schema.org Types
- ChemicalSubstance — Use for both substance and comparedTo
- AnatomicalStructure — Use when comparing to endogenous materials (e.g., sebum)
- Product — Use for commercial products being compared
- QuantitativeValue — Use for quantified similarity degrees
Validation Note
Schema.org Validators
Standard schema.org validators will not recognise CompositionComparison as it is a Health Schema custom type. This is expected behaviour.
CompositionComparison is designed for:
- Enhanced understanding by large language models
- Knowledge graph enrichment
- Precise semantic representation of biocompatibility and substitution rationales
Search engines will process standard schema.org properties normally and ignore custom extensions they don't understand.