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.
Psyllium
Selected research topic
Blood lipids
Findings differ across measurements or study conditions. The results below keep them separate.
Findings from a combination study cannot be attributed to this ingredient alone.
Some findings concern patients or people with a deficiency.
- Publications for this topic
- 23
- Human comparison publications
- 8
- Publications needing review
- 11
Findings in the studies
LDL cholesterol
Human comparison research
- 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.
- A better result than the comparison group was reported.Patient group · Separable contribution · 8 weeks
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
- Separable contribution
- How results were compared
- Results were compared between groups. · Study comparison: 10 mg simvastatin plus psyllium versus 10 mg simvastatin plus placebo
- Additional measurement information
- Primary outcome
- Measurement time
- 8 weeks
- A better result than the comparison group was reported.Patient group · Single ingredient · 8 weeks
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. · Between-group comparison
- Additional measurement information
- Primary outcome
- Measurement time
- 8 weeks
Other human research, including observational studies and reviews
- A change was reported, but the comparison could not be confirmed.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
Combination studyMeasurement 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
- Ingredient combination
- Measurement time
- Not confirmed.
plasma LDL-cholesterol concentration
- 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.
ratio of total cholesterol to high-density lipoprotein cholesterol
- A better result than the comparison group was reported.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
Patient group · Combination study · 10 weeksMeasurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Patient group
- Ingredients tested
- Ingredient combination
- How results were compared
- Results were compared between groups. · Between-group comparison
- Additional measurement information
- Secondary outcome
- Measurement time
- 10 weeks
serum total cholesterol
Human comparison research
- A better result than the comparison group was reported.
What the comparison group used was not confirmed.
Patient group · Single ingredientMeasurement 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.
- Measurement time
- Not confirmed.
Other human research, including observational studies and reviews
- A change was reported before and after use. Its cause cannot be isolated.Patient group · Single ingredient · after 3 months
Measurement and study conditions
- Study type
- Clinical trial
- Study population
- Human participants · Patient group
- Ingredients tested
- Single ingredient
- How results were compared
- Changes within the same group were compared. · Study comparison: within-group after-treatment change; no control group described
- Measurement time
- after 3 months
Other measured outcomes (4)
serum total, LDL, and HDL cholesterol
- Results were mixed for this outcome.Patient group · Single ingredient · three 2-week periods
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: psyllium mixed with cereal versus wheat-bran control; between-meal psyllium versus control
- Additional measurement information
- Primary outcome
- Measurement time
- three 2-week periods
TC levels
- A better result than the comparison group was reported.Patient group · Single ingredient · 3 months after dietary lead-in
Measurement and study conditions
- Study type
- Controlled trial
- Study population
- Human participants · Patient group
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups. · Study comparison: psyllium plus phase I diet versus diet alone
- Additional measurement information
- Primary outcome
- Measurement time
- 3 months after dietary lead-in
Serum cholesterol concentration
Other human research, including observational studies and reviews
- A change was reported, but the comparison could not be confirmed.Single ingredient
Measurement and study conditions
- Study type
- Clinical trial
- Study population
- Human participants · Participant characteristics were not confirmed.
- Ingredients tested
- Single ingredient
- Measurement time
- Not confirmed.
Total cholesterol
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
Measurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · General population
- Ingredients tested
- Single ingredient
- How results were compared
- Changes within the same group were compared. · Study comparison: within-person timing crossover; no cholesterol-lowering vs baseline observed
- Additional measurement information
- Secondary outcome
- Measurement time
- 8-week morning and evening periods
This result is held for interpretation. That does not mean research found no effect.
Outcome groups needing additional review (1)
- Cholesterol · 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.
Representative outcome and study details
Partial research summary
Human studies reported both between-group improvement and a change with no confirmed comparison group for LDL cholesterol.
These conditions come from related studies and may not describe a single paper.
single- and combination-ingredient studies · Individual ingredient effects cannot be separated · Human studies · Includes patient groups · Population not specified · between-group comparison · within-group comparison · comparator not confirmed
5 publications linked to this result (1 awaiting review included)
- 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.
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 65.0 evidence score includes 1 independent human studies and 1 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: 84
Papers linked to this topic 23 · distinct papers 23 · papers with a confirmed human comparison 8 · papers needing additional review 11
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.
- Cholesterol: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- LDL cholesterol: Sources represented in this measurement group: 5 · Distinct papers with human comparisons for this outcome: 3
- plasma LDL-cholesterol concentration: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- ratio of total cholesterol to high-density lipoprotein cholesterol: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- Serum cholesterol concentration: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- serum total cholesterol: Sources represented in this measurement group: 2 · Distinct papers with human comparisons for this outcome: 1
- serum total, LDL, and HDL cholesterol: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- TC levels: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- Total cholesterol: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
What the research found
serum total, LDL, and HDL cholesterol
Results for this measurement were mixed; no consistent conclusion can be drawn.
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 cholesterol
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.
LDL cholesterol
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.
LDL-C
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.
LDL-C
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.
plasma LDL-cholesterol concentration
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.
ratio of total cholesterol to high-density lipoprotein cholesterol
The study reported improvement in this measurement.
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.
serum total cholesterol
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.
TC levels
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.
serum total cholesterol
A change was reported before and after use. Its cause cannot be isolated.
Other evidence · Single ingredient · 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.
LDL cholesterol
A change was reported, but the comparison could not be confirmed.
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.
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.
Serum cholesterol concentration
A change was reported, but the comparison could not be confirmed.
Other evidence · 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.
Cholesterol
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.
LDL-C
The study needs further checking before its result can be interpreted.
Controlled study in people · Separable contribution · 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.
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.
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.
Controlled study in people · Single ingredient · Patient group
Between-group comparison
Analysis coverage and paper counts
5 papers · 5 measured outcomes
5 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.
Meta-analysis · 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.
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.
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.
small bowel obstruction1 papers
Four patients experienced small bowel obstruction after oral psyllium seed husk use as a contrast agent.Human studies · Study type not identifiedIntestinal obstruction1 papers
Psyllium ingestion without adequate fluids caused intestinal obstruction in a 21‑year‑old man.Human studies · Observational study