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.
Rhodiola
Selected research topic
Fatigue and energy
Some human comparison studies reported less favorable results than the comparison group. The populations and conditions matter.
Some findings concern patients or people with a deficiency.
- Publications for this topic
- 4
- Human comparison publications
- 1
- Publications needing review
- 2
Findings in the studies
Vitality-subscale
Publications linked to this measurement: 1
- A worse result than the comparison group was reported.Patient group · Single ingredient · 42 days
Measurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Patient group
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups. · Study comparison: Rhodiola rosea versus identical placebo
- Additional measurement information
- Primary outcome
- Measurement time
- 42 days
mental fatigue
Publications linked to this measurement: 1
Other human research, including observational studies and reviews
- A result was reported, but the comparison could not be confirmed.Single ingredient
Measurement 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
- Measurement time
- Not confirmed.
This result is held for interpretation. That does not mean research found no effect.
Outcome groups needing additional review (7)
- 5 km run · Distinct papers needing additional review: 1Direction unclear: 1
- heart rate 60 s after the simulated game · Distinct papers needing additional review: 1Direction unclear: 1
- RPE score · Distinct papers needing additional review: 1Direction unclear: 1
- total antioxidant capacity · Distinct papers needing additional review: 1Direction unclear: 1
- total completion time in the simulated game · Distinct papers needing additional review: 1Direction unclear: 1
- VO2max · Distinct papers needing additional review: 1Direction unclear: 1
- YO-YO test · 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
Human studies reported a result with no confirmed comparison group in mental fatigue.
Single-ingredient studies · Human studies · Population not specified · comparator not confirmed
1 publications linked to this result
- Route, form, dose, or population details are incomplete, so the findings cannot be confirmed as directly comparable.
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 60.9 evidence score includes 8 independent human studies and 8 clinical studies in the representative benefit area. The B 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: 92
Papers linked to this topic 4 · distinct papers 4 · papers with a confirmed human comparison 1 · papers needing additional review 2
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.
- 5 km run: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- heart rate 60 s after the simulated game: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- mental fatigue: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- RPE score: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- total antioxidant capacity: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- total completion time in the simulated game: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Vitality-subscale: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- VO2max: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- YO-YO test: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
What the research found
Vitality-subscale
The study reported a less favorable result than the comparison for 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.
mental fatigue
A result was reported, but the comparison could not be confirmed.
Controlled study in people · Single ingredient · Unspecified population
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.
5 km run
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.
heart rate 60 s after the simulated game
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.
RPE score
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.
total antioxidant capacity
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.
total completion time in the simulated game
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.
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.
VO2max
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.
YO-YO test
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.
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 reviewed caution rules are available yet. Reported caution findings are shown below.
Review 1 combination findings and 0 findings that outperformed an ingredient alone.
Findings to review with care
Side effects reported for the ingredient alone are separated from findings involving another supplement or medication.
Cautions reported with another supplement or medication
These studies reported worsening outcomes, reduced absorption, or other cautions with combined use. They do not predict an individual's outcome.
SSRIsPotential risk of serotonin syndrome when combined with SSRIs.
Tricyclic antidepressantsPotential risk of serotonin syndrome when combined with tricyclic antidepressants.
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.
CaffeineA randomized, double-blind, placebo-controlled trial in 48 male volleyball players found that combined Rhodiola rosea and caffeine supplementation significantly improved jump height, reduced power decline during high-frequency jumps, and lowered perceived exertion compared to placebo and single-agent groups.