Improvement after a supplement is not the same as a comparative result
Start with the comparison. A before-and-after change alone cannot isolate the contribution of an ingredient.
Collagen
Selected research topic
Skin, hair, and nails
Some measured outcomes improved in human comparison studies. Read these findings with their populations and conditions.
Findings from a combination study cannot be attributed to this ingredient alone.
Animal and cell findings do not establish the same effect in people.
- Publications for this topic
- 31
- Human comparison publications
- 2
- Publications needing review
- 24
Findings in the studies
type II collagen degradation peptide
- A better result than the comparison group was reported.
What the comparison group used was not confirmed.
Single ingredientMeasurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Participant characteristics were not confirmed.
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups.
- Measurement time
- Not confirmed.
wrinkles
- A better result than the comparison group was reported.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
General population · Combination study · 90 daysMeasurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · General population
- Ingredients tested
- Ingredient combination
- How results were compared
- Results were compared between groups. · Study comparison: Hydrolyzed fish cartilage vs placebo and baseline
- Additional measurement information
- Primary outcome
- Measurement time
- 90 days
Intramuscular Collagen
Animal and cell research · indirect evidence
- A change was reported in animal or cell research.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
Combination studyMeasurement and study conditions
- Study type
- Animal study · indirect
- Study population
- This is animal research. The specific characteristics of the subjects need further review.
- Ingredients tested
- Ingredient combination
- How results were compared
- Comparison unclear
- Measurement time
- Not confirmed.
clinical manifestation of skin health
Research with unclear study subject or type
- A change was reported, but the comparison could not be confirmed.Single ingredient · Varied across included studies
Measurement and study conditions
- Study type
- Systematic review
- Study population
- Study subject not identified
- Ingredients tested
- Single ingredient
- How results were compared
- Study comparison: Review-level collagen supplementation findings across included skin studies
- Measurement time
- Varied across included studies
Other measured outcomes (2)
Collagen content
Research with unclear study subject or type
- A change was reported, but the comparison could not be confirmed.
Measurement and study conditions
- Study type
- Meta-analysis
- Study population
- Study subject not identified
- Ingredients tested
- Unknown intervention
- Measurement time
- Not confirmed.
Skin hydration
Research with unclear study subject or type
- The study reported improvement in this measurement.
What the comparison group used was not confirmed.
Single ingredientMeasurement and study conditions
- Study type
- Meta-analysis
- Study population
- Study subject not identified
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups.
- Measurement time
- Not confirmed.
This result is held for interpretation. That does not mean research found no effect.
Outcome groups needing additional review (4)
- collagen deposition · Distinct papers needing additional review: 1Evidence criteria check: 1
- healing rate · Distinct papers needing additional review: 1Evidence criteria check: 1
- Skin elasticity · Distinct papers needing additional review: 2Direction unclear: 1 · Evidence criteria check: 1
- water content · Distinct papers needing additional review: 1Direction unclear: 1
One paper can appear under multiple measured outcomes or review reasons, so these counts should not be added together.
Representative outcome and study details
Studies with an unspecified organism reported between-group improvement in Skin hydration.
These conditions come from related studies and may not describe a single paper.
Single-ingredient studies · Population not specified · between-group comparison
2 publications linked to this result
- Study conditions differ; results are shown descriptively and are not pooled.
Data coverage and detailed study classifications
Paper counts are separated by research topic below. One paper may contribute to multiple findings.
Analysis status: Public-ready
Ingredient analysis date:
How the grade was determined: B
The 60.0 evidence score includes 3 independent human studies and 2 clinical studies in the representative benefit area. The B tier remains conservative because of limited repetition across independent human clinical studies, too few clinical findings with an explicit effect direction.
The grade is based mainly on the research area with the most evidence. It does not mean the same result was found in other areas.
Papers linked to this ingredient overall: 105
Papers linked to this topic 31 · distinct papers 31 · papers with a confirmed human comparison 2 · papers needing additional review 24
A publication may appear in more than one count. These numbers should not be added. Ingredient-wide papers, topic-linked papers, and sources in outcome groups use different scopes. Adding source counts may count the same paper more than once.
- clinical manifestation of skin health: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Collagen content: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- collagen deposition: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- healing rate: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Intramuscular Collagen: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Skin elasticity: Sources represented in this measurement group: 2 · Distinct papers with human comparisons for this outcome: 0
- Skin hydration: Sources represented in this measurement group: 2 · Distinct papers with human comparisons for this outcome: 0
- type II collagen degradation peptide: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- water content: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- wrinkles: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
What the research found
type II collagen degradation peptide
The study reported improvement in this measurement.
Controlled study in people · Single ingredient · Unspecified population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
wrinkles
The study reported improvement in this measurement.
Controlled study in people · Ingredient combination · General population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Skin hydration
The study reported improvement in this measurement.
Meta-analysis · Single ingredient · Unspecified population
Between-group comparison
Analysis coverage and paper counts
2 papers · 2 measured outcomes
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
clinical manifestation of skin health
A change was reported, but the comparison could not be confirmed.
Review · Single ingredient · Unspecified population
Analysis coverage and paper counts
1 paper · 1 measured outcome
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Collagen content
A change was reported, but the comparison could not be confirmed.
Meta-analysis · Unknown intervention · Unspecified population
Analysis coverage and paper counts
1 paper · 1 measured outcome
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Intramuscular Collagen
A change was reported in animal or cell research.
Animal study · indirect · Ingredient combination · Unspecified population
This finding comes from animal or cell research. It does not establish the same effect in people.
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
collagen deposition
The study needs further checking before its result can be interpreted.
Animal study · indirect · Ingredient combination · Patient group
This finding comes from animal or cell research. It does not establish the same effect in people.
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
healing rate
The study needs further checking before its result can be interpreted.
Animal study · indirect · Ingredient combination · Patient group
This finding comes from animal or cell research. It does not establish the same effect in people.
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Skin elasticity
The study needs further checking before its result can be interpreted.
Controlled study in people · Ingredient combination · Unspecified population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
skin elasticity
The study needs further checking before its result can be interpreted.
Other evidence · Ingredient combination · General population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Cell study · indirect · Ingredient combination · Unspecified population
This finding comes from animal or cell research. It does not establish the same effect in people.
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Other evidence · Ingredient combination · Patient group
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Animal study · indirect · Separable contribution · Unspecified population
This finding comes from animal or cell research. It does not establish the same effect in people.
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Animal study · indirect · Single ingredient · Patient group
This finding comes from animal or cell research. It does not establish the same effect in people.
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Animal study · indirect · Single ingredient · Unspecified population
This finding comes from animal or cell research. It does not establish the same effect in people.
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · Patient group
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · Unspecified population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Other evidence · Single ingredient · Unspecified population
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Other evidence · Single ingredient · Unspecified population
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Review · Single ingredient · Unspecified population
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Observational study · Unknown intervention · Patient group
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Other evidence · Unknown intervention · Patient group
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Other evidence · Unknown intervention · Patient group
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Other evidence · Unknown intervention · Unspecified population
The comparison could not be confirmed.
Analysis coverage and paper counts
2 papers · 2 measured outcomes
2 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Other evidence · Unknown intervention · Unspecified population
The comparison could not be confirmed.
Analysis coverage and paper counts
2 papers · 2 measured outcomes
2 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Review · Unknown intervention · Patient group
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Review · Unknown intervention · Unspecified population
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
water content
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · General population
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
How to read research findings
How should I read research findings?
Research guidesNo clear difference and an uninterpretable result are different
A reported null comparison contains a result. An abstract without an interpretable comparison leaves a question unresolved.
Paper counts and study counts are different
Count original research separately from research that reanalyzes it. Publication volume is neither replication nor a quality rating.
Side effects and combination findings
Findings from this ingredient alone are shown separately from those involving another supplement or medication.
No combination cautions are available to show in the current data. This does not guarantee safety.
Side effects and combination studies
No side-effect or combination findings are available to show from the collected papers. This does not establish safety.