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Bacopa monnieri and processing speed: grade C

Limited evidence. Direction: No effect.

Short-term only

Educational guidance, not medical advice

Why this grade

Rubric condition met: Conflicting syntheses: a 2014 meta-analysis that mixes healthy and impaired participants (no healthy-only estimate) is positive, while a 2026 network meta-analysis of 29 RCTs in healthy adults found no statistically significant differences; the population cap caps at C and the mixed results give direction none

A 2014 meta-analysis of trials lasting 12 weeks or more found a shorter Trail B time and concluded bacopa may improve speed of attention; its reaction-time figure is internally inconsistent and is not cited. A 2026 network meta-analysis restricted to healthy adults found no significant differences in sustained attention, selective attention or processing speed. Single trials disagree. Evidence is mixed, so the more conservative grade applies.

How we grade evidence

Studies this grade rests on

EffectMixedNo effectSize shows participants (n)2000200520102015202020252030Meta-analysisRCTTiemtad 2026, 2026: meta-analysis, n = 2,107, result not recordedKongkeaw 2014, 2014: meta-analysis, n = 518, result not recordedLopresti 2025, 2025: RCT, n = 101, result not recordedRoodenrys 2002, 2002: RCT, n = 76, result not recordedStough 2001, 2001: RCT, n not recorded, result not recorded
each study this grade rests on, by publication year and design. Solid: effect versus the comparator; half-filled: mixed; hollow: no effect; dashed: result not recorded yet. Larger marks had more participants.
Show the numbers
StudyYearDesignParticipantsResult
Stough 20012001RCTnot recordedresult not recorded
Roodenrys 20022002RCT76result not recorded
Kongkeaw 20142014meta-analysis518result not recorded
Lopresti 20252025RCT101result not recorded
Tiemtad 20262026meta-analysis2107result not recorded

The Effects of a Bacopa monnieri Extract (Bacumen(®)) on Cognition, Stress, and Fatigue in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Trial.

Lopresti AL, Smith SJ. The Effects of a Bacopa monnieri Extract (Bacumen(®)) on Cognition, Stress, and Fatigue in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Trial Clin Drug Investig, 2025. PMID 41091332

Result not recorded
Design
Randomized, double-blind, placebo-controlled parallel-group trial (12 weeks)
Sample
n = 101
Population
Adults aged 40-70 with self-reported memory and attention problems
Funding
US Pharma Lab (Crossref funder record)

Chronic effects of Brahmi (Bacopa monnieri) on human memory.

Roodenrys S, Booth D, Bulzomi S. Chronic effects of Brahmi (Bacopa monnieri) on human memory Neuropsychopharmacology, 2002. PMID 12093601

Result not recorded
Design
Randomized, double-blind, placebo-controlled trial (3 months plus 6-week follow-up)
Sample
n = 76
Population
Healthy adults aged 40-65
Funding
not stated in PubMed/Crossref records

The chronic effects of an extract of Bacopa monniera (Brahmi) on cognitive function in healthy human subjects.

Stough C, Lloyd J, Clarke J. The chronic effects of an extract of Bacopa monniera (Brahmi) on cognitive function in healthy human subjects Psychopharmacology (Berl), 2001. PMID 11498727

Result not recorded
Design
Randomized, double-blind, placebo-controlled parallel-group trial (12 weeks)
Population
Healthy adults
Funding
not stated in PubMed/Crossref records; extract (Keenmind) information supplied by the manufacturer per the erratum

Comparative effects of Bacopa monnieri and Ginkgo biloba on cognitive functions: A systematic review and network meta-analysis.

Tiemtad P, Ingkaninan K, Temkitthawon P. Comparative effects of Bacopa monnieri and Ginkgo biloba on cognitive functions: A systematic review and network meta-analysis Phytomedicine, 2026. PMID 41678913

Result not recorded
Design
Systematic review and network meta-analysis of 29 RCTs (PROSPERO CRD420251034900)
Sample
n = 2,107
Population
Healthy adults
Funding
Thailand Research Fund (Royal Golden Jubilee Ph.D. Program)

Meta-analysis of randomized controlled trials on cognitive effects of Bacopa monnieri extract.

Kongkeaw C, Dilokthornsakul P, Thanarangsarit P. Meta-analysis of randomized controlled trials on cognitive effects of Bacopa monnieri extract J Ethnopharmacol, 2014. PMID 24252493

Result not recorded
Design
Meta-analysis of randomized placebo-controlled trials (9 trials, chronic dosing of 12 weeks or more)
Sample
n = 518
Population
Adults in trials of standardized extracts (healthy and impaired participants; abstract does not split)
Funding
not stated (no grant or funder in PubMed or Crossref records)

Search and history

Search (): bacopa[ti] AND (attention[tiab] OR "reaction time"[tiab] OR acute[tiab]) AND (randomized controlled trial[pt] OR clinical trial[pt])

  • Graded C (awaiting approval)
  • C to C (awaiting approval)
  • C to C (approved): Editor sign-off November 13, 2026: grade matches the editor-approved final page