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.
5-HTP
Stress and mood
Studies with an unspecified organism reported between-group improvement in depression.
combination-ingredient studies · Individual ingredient effects cannot be separated · Includes patient groups · between-group comparison
Publications for this result: 1
Other outcomes and study details
Distinct publications linked to this topic: 11
- Route, form, dose, or population details are incomplete, so the findings cannot be confirmed as directly comparable.
- Combination, formula, or class studies do not isolate this ingredient or establish synergy.
What has been studied?
Distinct human comparison papers: 0
Some studies tested several ingredients together. Those results cannot show this ingredient’s separate effect or establish synergy.
depression
Research with unclear study subject or type
- The study reported improvement in this measurement.Patient group · Combination study
Measurement and study conditions
- Review
- Systematic review
- Ingredient combination
- Patient group
- Outcome role not specified
- Between-group comparison
- Study subject not identified
- Timepoint: unspecified
- Study comparison: 5-HTP and tryptophan evidence pooled versus placebo
depression remission
Research with unclear study subject or type
- A change was reported, but the comparison could not be confirmed.Patient group · Single ingredient · varied across included studies
Measurement and study conditions
- Meta-analysis
- Meta-analysis
- Single ingredient
- Patient group
- Primary outcome
- Study subject not identified
- Timepoint: varied across included studies
- Study comparison: Across included 5-hydroxytryptophan investigations; few placebo groups
GDS score
Other human research, including observational studies and reviews
- A change was reported before and after use. Its cause cannot be isolated.General population · Single ingredient · 8 weeks
Measurement and study conditions
- Controlled human study
- Randomized trial
- Single ingredient
- General population
- Secondary outcome
- Within-group comparison
- Timepoint: 8 weeks
- Study comparison: Within-5-HTP-group GDS change; between-group effect not reported
romantic stress scores
Other human research, including observational studies and reviews
- A change was reported before and after use. Its cause cannot be isolated.General population · Combination study
Measurement and study conditions
- Other evidence
- Clinical trial
- Ingredient combination
- General population
- Outcome role not specified
- Within-group comparison
- Timepoint: weeks 0 to 3; no further significant improvement weeks 3 to 6
- Study comparison: within-participant change from baseline; no control group
This result is held for interpretation. That does not mean research found no effect.
Outcome groups needing additional review (3)
- cortisol concentrations · Distinct papers needing additional review: 1Direction unclear: 1
- cortisol response AUC(0-3h) · Distinct papers needing additional review: 1Direction unclear: 1
- HAM-D scores · Distinct papers needing additional review: 1Evidence criteria check: 1
One paper can appear under multiple measured outcomes or review reasons, so these counts should not be added together.
Research topics to explore
Research topics to explore
Review findings reported in each research area.
Topics with more linked papers appear first.
- View selected result
Stress and mood
Related papers 11 · comparison findings need further review
- View results
Cognition
Related papers 2 · comparison findings need further review
- looking duration · Interpretation held
- MoCA score · Finding details are limited
- View results
Glucose and metabolic health
Related papers 2 · human comparison papers 1
- Fat mass · Improvement reported
- Weight loss · Interpretation held
- View results
Sleep
Related papers 2 · comparison findings need further review
- subjective GSS · Interpretation held
- View results
Digestion and gut health
Related papers 1 · comparison findings need further review
- diversity · Interpretation held
- View results
Fatigue and energy
Related papers 1 · comparison findings need further review
- View results
Immune and respiratory health
Related papers 1 · comparison findings need further review
- S-IRA · Interpretation held
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: C
The 45.9 evidence score includes 1 independent human studies and 1 clinical studies in the representative benefit area. The C 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: 56
Papers linked to this topic 11 · distinct papers 11 · comparison findings need further review · papers needing additional review 7
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.
- cortisol concentrations: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- cortisol response AUC(0-3h): Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- depression: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- depression remission: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- GDS score: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- HAM-D scores: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- romantic stress scores: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
Stress and mood
What the research found
GDS score
A change was reported before and after use. Its cause cannot be isolated.
Controlled study in people · Single ingredient · General population
Within-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.
depression
The study reported improvement in this measurement.
Review · Ingredient combination · Patient group
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
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.
romantic stress scores
A change was reported before and after use. Its cause cannot be isolated.
Other evidence · Ingredient combination · General population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Within-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.
depression remission
A change was reported, but the comparison could not be confirmed.
Meta-analysis · Single ingredient · Patient group
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.
cortisol concentrations
The study needs further checking before its result can be interpreted.
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
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.
cortisol response AUC(0-3h)
The study needs further checking before its result can be interpreted.
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.
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.
HAM-D scores
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.
Within-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.
Controlled study in people · Single ingredient · Patient group
Between-group comparison
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.
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 human study · Unknown intervention · Unspecified population
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.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Meta-analysis · Unknown intervention · Patient group
Between-group comparison
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.
Cognition
What the research found
MoCA score
A change was reported before and after use. Its cause cannot be isolated.
Controlled study in people · Single ingredient · General population
Within-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.
looking duration
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.
Within-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.
Glucose and metabolic health
What the research found
Fat mass
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.
Weight loss
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.
Sleep
What the research found
subjective GSS
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · Unspecified population
Within-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.
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.
Digestion and gut health
What the research found
diversity
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.
Fatigue and energy
What the research found
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · 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.
Immune and respiratory health
What the research found
S-IRA
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.
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.
Caution findings
1
Findings from individual and combined use, plus reviewed cautions
Key precautions
No reviewed caution rules are available yet. Reported caution findings are shown below.
These findings were reported in studies. They do not predict an individual's experience.
Findings to review with care
Side effects reported for the ingredient alone are separated from findings involving another supplement or medication.
Side effects reported with this ingredient alone
Symptoms or adverse events reported in studies without another active ingredient.
distractibility1 papers
Acute 5-hydroxytryptophan administration did not produce a significant positive effect on distractibility in adults with high or low ADHD traits, and 19.6% experienced fatigue, nausea, or vomiting.Human studies · Randomized controlled trial