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Ginkgo biloba and attention: grade N

No benefit shown evidence. Direction: No effect.

N No benefit shown

Educational guidance, not medical advice

Why this grade

Rubric condition met: Adequate human RCTs found no meaningful effect: meta-analysis of 8 RCTs (910 participants) in healthy individuals, null; small acute crossover trials positive but not replicated

Pooled attention data from 8 RCTs (910 healthy participants) showed a non-significant effect close to zero (d = -0.08), and a 2026 network meta-analysis of 29 RCTs found no significant differences in sustained or selective attention. Small single-dose trials reported faster or better attention hours after a dose, but a 6-week arm in the same study found no effect, and a systematic review found acute positives were not replicated. The acute positives are reported in the section but not graded separately.

How we grade evidence

Studies this grade rests on

EffectMixedNo effectSize shows participants (n)2000200520102015202020252030Meta-analysisSystematic reviewRCTCrossover RCTTiemtad 2026, 2026: meta-analysis, n = 2,107, result not recordedLaws 2012, 2012: meta-analysis, n = 1,132, result not recordedElsabagh 2005, 2005: RCT, n = 92, result not recordedKennedy 2000, 2000: crossover RCT, n = 20, result not recordedCanter 2007, 2007: systematic review, 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
Kennedy 20002000crossover RCT20result not recorded
Elsabagh 20052005RCT92result not recorded
Canter 20072007systematic reviewnot recordedresult not recorded
Laws 20122012meta-analysis1132result not recorded
Tiemtad 20262026meta-analysis2107result not recorded

Differential cognitive effects of Ginkgo biloba after acute and chronic treatment in healthy young volunteers.

Elsabagh S, Hartley DE, Ali O. Differential cognitive effects of Ginkgo biloba after acute and chronic treatment in healthy young volunteers Psychopharmacology (Berl), 2005. PMID 15739076

Result not recorded
Design
Two placebo-controlled double-blind randomized experiments (single dose; 6 weeks)
Sample
n = 92
Population
Healthy university students
Funding
Dunhill Medical Trust (publisher full text, acknowledgements, read 2026-11-11)

The dose-dependent cognitive effects of acute administration of Ginkgo biloba to healthy young volunteers.

Kennedy DO, Scholey AB, Wesnes KA. The dose-dependent cognitive effects of acute administration of Ginkgo biloba to healthy young volunteers Psychopharmacology (Berl), 2000. PMID 11026748

Result not recorded
Design
Placebo-controlled, multi-dose, double-blind, balanced crossover trial
Sample
n = 20
Population
Healthy young volunteers
Funding
not stated (PubMed and Crossref records)

Ginkgo biloba is not a smart drug: an updated systematic review of randomised clinical trials testing the nootropic effects of G. biloba extracts in healthy people.

Canter PH, Ernst E. Ginkgo biloba is not a smart drug: an updated systematic review of randomised clinical trials testing the nootropic effects of G. biloba extracts in healthy people Hum Psychopharmacol, 2007. PMID 17480002

Result not recorded
Design
Systematic review of 15 randomized, placebo-controlled, double-blind trials
Population
Healthy people under 60 years
Funding
not stated (PubMed and Crossref records)

Is Ginkgo biloba a cognitive enhancer in healthy individuals? A meta-analysis.

Laws KR, Sweetnam H, Kondel TK. Is Ginkgo biloba a cognitive enhancer in healthy individuals? A meta-analysis Hum Psychopharmacol, 2012. PMID 23001963

Result not recorded
Design
Meta-analysis of randomized controlled trials (memory k=13, executive function k=7, attention k=8)
Sample
n = 1,132
Population
Healthy individuals
Funding
not stated (PubMed and Crossref records)

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)

Search and history

Search (): ginkgo[ti] AND acute[tiab] AND (cognitive[tiab] OR attention[tiab]) AND healthy young[tiab] AND randomized controlled trial[pt]

  • Graded N (proposed): Proposed in the monograph draft
  • N to N (approved): Editor sign-off November 13, 2026: grade matches the editor-approved final page