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.
L-Theanine
Sleep
Partial research summary
Human studies reported between-group improvement in sleep efficiency.
single- and combination-ingredient studies · Individual ingredient effects cannot be separated · Human studies · Includes patient groups · between-group comparison · comparator not confirmed
Publications for this result: 2 (1 awaiting review included)
Other outcomes and study details
Distinct publications linked to this topic: 15
- Study conditions differ; results are shown descriptively and are not pooled.
- Combination, formula, or class studies do not isolate this ingredient or establish synergy.
- Some publications have not cleared source or interpretation review.
- Some papers could not be reviewed, so this summary covers only findings that could be confirmed.
What has been studied?
Distinct human comparison papers: 3
Some studies tested several ingredients together. Those results cannot show this ingredient’s separate effect or establish synergy.
Insomnia symptoms
Insomnia Severity Index (ISI)
- Comparison result:No clear difference from the comparison group was found.Single ingredient
Measurement and study conditions
- Controlled human study
- Randomized trial
- Single ingredient
- Unspecified population
- Outcome role not specified
- Between-group comparison
- Timepoint: unspecified
- Study comparison: unspecified
Sleep quality
Pittsburgh Sleep Quality Index (PSQI) · mean score
- Comparison result:No clear difference from the comparison group was found.Patient group · Combination study · 6 weeks
Measurement and study conditions
- Controlled human study
- Randomized trial
- Ingredient combination
- Patient group
- Primary outcome
- Between-group comparison
- Timepoint: 6 weeks
- Study comparison: four-ingredient formulation versus placebo
sleep efficiency
- Comparison result:A better result than the comparison group was reported.Patient group · Single ingredient
Measurement and study conditions
- Controlled human study
- Randomized trial
- Single ingredient
- Patient group
- Outcome role not specified
- Between-group comparison
- Timepoint: unspecified
- Study comparison: unspecified
sleep-onset latency
Research with unclear study subject or type
- A change was reported, but the comparison could not be confirmed.Patient group · Varied across included studies
Measurement and study conditions
- Review
- Systematic review
- Unknown intervention
- Patient group
- Secondary outcome
- Study subject not identified
- Timepoint: Varied across included studies
- Study comparison: Mixed ADHD treatments including L-theanine; no common comparator
Other measured outcomes (1)
Sleep quality
Pittsburgh Sleep Quality Index (PSQI) · total score
Other human research, including observational studies and reviews
- A change was reported before and after use. Its cause cannot be isolated.Patient group · Combination study · 4 weeks
Measurement and study conditions
- Other evidence
- Clinical trial
- Ingredient combination
- Patient group
- Primary outcome
- Within-group comparison
- Timepoint: 4 weeks
- Study comparison: within-group pre/post combination intake
This result is held for interpretation. That does not mean research found no effect.
Outcome groups needing additional review (10)
- morning sleepiness · Distinct papers needing additional review: 1Direction unclear: 1
- overall subjective sleep quality score · Distinct papers needing additional review: 1Evidence criteria check: 1
- sleep duration · Distinct papers needing additional review: 2Evidence criteria check: 2
- sleep latency · Distinct papers needing additional review: 1Evidence criteria check: 1
- sleep onset latency · Distinct papers needing additional review: 2Direction unclear: 1 · Evidence criteria check: 1
- sleep problems · Distinct papers needing additional review: 1Direction unclear: 1
- Sleep quality · Distinct papers needing additional review: 1Direction unclear: 1
- subjective daytime dysfunction · Distinct papers needing additional review: 1Evidence criteria check: 1
- subjective sleep onset latency · Distinct papers needing additional review: 1Evidence criteria check: 1
- total sleep time · 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.
Research topics to explore
Research topics to explore
Review findings reported in each research area.
Topics with more linked papers appear first.
- View results
Stress and mood
Related papers 17 · human comparison papers 2
- HDRS · Improvement reported · Some studies included patients or people with a deficiency
- markers of stress · No clear difference between groups
More outcome groups: 10
- View selected result
Sleep
Related papers 15 · human comparison papers 3
- View results
Cognition
Related papers 7 · comparison findings need further review
- Attention · Interpretation held
- attention on a switch task · Interpretation held
More outcome groups: 6
- View results
Glucose and metabolic health
Related papers 2 · comparison findings need further review
- Body weight · Interpretation held
- muscle glycogen · Interpretation held
- View results
Blood lipids
Related papers 1 · comparison findings need further review
- serum levels of cholesterol · Interpretation held
- triglycerides · Interpretation held
- View results
Blood pressure and vascular health
Related papers 1 · comparison findings need further review
- blood-pressure increases · Interpretation held
- View results
Digestion and gut health
Related papers 1 · comparison findings need further review
- intestinal inflammation · Interpretation held
- View results
Exercise performance
Related papers 1 · comparison findings need further review
- View results
Fatigue and energy
Related papers 1 · comparison findings need further review
- self-reported tiredness · Interpretation held
- View results
Immune and respiratory health
Related papers 1 · comparison findings need further review
- splenic organ index · Interpretation held
- View results
Nutrient status
Related papers 1 · comparison findings need further review
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 9.4 evidence score includes 3 independent human studies and 3 clinical studies in the representative benefit area. The C tier remains conservative because of limited repetition across independent human clinical studies.
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: 97
Papers linked to this topic 15 · distinct papers 15 · papers with a confirmed human comparison 3 · papers needing additional review 10
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.
- Insomnia symptoms (Insomnia Severity Index (ISI)): Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- Sleep quality (Pittsburgh Sleep Quality Index (PSQI) · mean score): Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- morning sleepiness: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- overall subjective sleep quality score: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- sleep duration: Sources represented in this measurement group: 2 · Distinct papers with human comparisons for this outcome: 0
- sleep efficiency: Sources represented in this measurement group: 2 · Distinct papers with human comparisons for this outcome: 1
- sleep latency: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- sleep onset latency: Sources represented in this measurement group: 2 · Distinct papers with human comparisons for this outcome: 0
- sleep problems: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Sleep quality: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- sleep-onset latency: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- subjective daytime dysfunction: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- subjective sleep onset latency: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Sleep quality (Pittsburgh Sleep Quality Index (PSQI) · total score): Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- total sleep time: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
Stress and mood
What the research found
markers of stress
No clear difference in this measurement was found between the compared groups.
Controlled study in people · Separable contribution · General 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.
HDRS
The study reported improvement in this measurement.
Controlled study in people · Separable contribution · Patient group
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.
HAMD-21 score
A change was reported before and after use. Its cause cannot be isolated.
Other evidence · Separable contribution · Patient group
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.
anti-stress effects
The study needs further checking before its result can be interpreted.
Review · Ingredient combination · Unspecified 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
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.
anxiolytic and calming effect
The study needs further checking before its result can be interpreted.
Review · Unknown intervention · General 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.
DASS-42 stress score
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.
depression
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.
depressive-like behaviors
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.
overall mood
The study needs further checking before its result can be interpreted.
Meta-analysis · 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
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.
state anxiety
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.
subjective stress response to a multitasking cognitive stressor
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.
Tension-Anxiety scores
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · General 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.
Review · Single ingredient · Unspecified population
The comparison could not be confirmed.
Analysis coverage and paper counts
2 papers · 2 measured outcomes
2 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 · 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.
Other evidence · 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
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
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.
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.
Sleep
What the research found
Insomnia Severity Index
No clear difference in this measurement was found between the compared groups.
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.
Mean PSQI
No clear difference in this measurement was found between the compared groups.
Controlled study in people · 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
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
sleep efficiency
The study reported improvement in this measurement.
Controlled study in people · Single ingredient · Patient group
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.
total PSQI score
A change was reported before and after use. Its cause cannot be isolated.
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
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
sleep-onset latency
A change was reported, but the comparison could not be confirmed.
Review · Unknown intervention · 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.
morning sleepiness
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.
overall subjective sleep quality score
The study needs further checking before its result can be interpreted.
Meta-analysis · Unknown intervention · General 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.
sleep duration
The study needs further checking before its result can be interpreted.
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.
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.
sleep duration
The study needs further checking before its result can be interpreted.
Animal study · indirect · Separable contribution · General 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.
sleep efficiency
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.
sleep latency
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · General 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.
sleep onset latency
The study needs further checking before its result can be interpreted.
Animal study · indirect · Ingredient combination · General 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.
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.
sleep onset latency
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.
sleep problems
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.
Sleep quality
The study needs further checking before its result can be interpreted.
Other evidence · 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.
subjective daytime dysfunction
The study needs further checking before its result can be interpreted.
Meta-analysis · Unknown intervention · General 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.
subjective sleep onset latency
The study needs further checking before its result can be interpreted.
Meta-analysis · Unknown intervention · General 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.
total sleep time
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.
Unspecified measured outcome
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.
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
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.
Cognition
What the research found
Attention
The study needs further checking before its result can be interpreted.
Review · 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
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.
attention on a switch task
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.
cognitive function
The study needs further checking before its result can be interpreted.
Review · Unknown intervention · General 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.
reaction time to attention tasks
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · General 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.
Rey-Kim memory quotient
The study needs further checking before its result can be interpreted.
Controlled study in people · 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
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.
speed and accuracy of performance of the attention-switching task
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.
susceptibility to distracting information in the memory task
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.
total cognition composite
The study needs further checking before its result can be interpreted.
Controlled study in people · 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
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.
total cognition composite
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.
Glucose and metabolic health
What the research found
Body weight
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.
muscle glycogen
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.
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.
Blood lipids
What the research found
serum levels of cholesterol
The study needs further checking before its result can be interpreted.
Animal study · indirect · Single ingredient · General 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.
triglycerides
The study needs further checking before its result can be interpreted.
Animal study · indirect · Single ingredient · General 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.
Blood pressure and vascular health
What the research found
blood-pressure increases
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · General 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.
Digestion and gut health
What the research found
intestinal inflammation
The study needs further checking before its result can be interpreted.
Animal study · indirect · Single ingredient · General 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.
Exercise performance
What the research found
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Controlled study in people · Unknown intervention · 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.
Fatigue and energy
What the research found
self-reported tiredness
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.
Immune and respiratory health
What the research found
splenic organ index
The study needs further checking before its result can be interpreted.
Animal study · indirect · Single ingredient · General 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.
Nutrient status
What the research found
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.
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
0
Findings from individual and combined use, plus reviewed cautions
Key precautions
No combination cautions are available to show in the current data. This does not guarantee safety.
Review 1 combination findings and 0 findings that outperformed an ingredient alone.
These findings were reported in studies. They do not predict an individual's experience.
Reported improvements with combinations
Combination findings are grouped by how the study compared them. This is not a recommendation to combine ingredients.
Combinations with reported improvement
The combination showed improvement, but each ingredient's contribution is unclear.
CaffeineL-theanine combined with caffeine significantly reduced caffeine-induced tachycardia (17% vs 92%) and state anxiety compared to caffeine alone.