Evidence Trace, complete trial record
In plain terms
In plain terms: Ginkgo Biloba (EGb 761) has some human trial evidence supporting it, but the evidence is not yet strong enough for EBL to call it established. It is worth knowing about and worth discussing with your clinician.
Ginkgo Biloba (EGb 761)
B
Supported: a good trial, backed by more
The endpoint this grade is based on: Objectively measured functional outcome, Cognitive symptoms in mild to moderate dementia, with the standardized extract EGb 761 at 240 mg a day
The evidence as the record states it
Tan et al. (Journal of Alzheimer's Disease, 2015; PMID 25114079): 9 randomized trials of EGb 761, 2,561 patients, 22 to 26 weeks; cognition, daily activities and clinician global impression favored EGb 761, mainly at 240 mg a day. Gauthier and Schlaefke (Clinical Interventions in Aging, 2014; PMID 25506211): 7 trials, cognition improved. Riepe et al. (World Journal of Biological Psychiatry, 2025; PMID 39895346): pooled subgroup analysis of 4 placebo-controlled trials in 782 patients with mild dementia at 240 mg a day. Liao et al. (Clinical Neuropharmacology, 2020; PMID 32658034): 7 studies, 939 patients with Alzheimer disease, of Ginkgo biloba preparations not named as EGb 761. Not every pool agrees: Birks and Grimley Evans (Cochrane Database of Systematic Reviews, 2009; PMID 19160216) judged the evidence inconsistent, and Thancharoen et al. (Drugs and Aging, 2019; PMID 30937879) found no benefit over placebo in mild to moderate Alzheimer disease. Several replicating trials and two of the pooled analyses have authors from the manufacturer. Gavrilova et al. (International Journal of Geriatric Psychiatry, 2014; PMID 24633934) is the one blinded trial in mild cognitive impairment.
PMID 25114079 PMID 25506211 PMID 39895346 PMID 32658034 PMID 19160216 PMID 30937879 PMID 24633934
Evidence by specific use
Cognitive symptoms in mild to moderate dementia
Grade B
Tan et al. (J Alzheimers Dis, 2015; PMID 25114079) and Gauthier and Schlaefke (Clin Interv Aging, 2014; PMID 25506211) found cognition improved; Riepe et al. (World J Biol Psychiatry, 2025; PMID 39895346) agrees in mild dementia. Birks and Grimley Evans (Cochrane, 2009; PMID 19160216) and Thancharoen et al. (Drugs Aging, 2019; PMID 30937879) dissent. Replicated trials with dissenting pools fit B, not A. The replicating trials are largely manufacturer-affiliated, which is disclosed here.
PMID 25114079 PMID 25506211 PMID 39895346 PMID 19160216 PMID 30937879
Mild cognitive impairment
Grade C
Gavrilova et al. (Int J Geriatr Psychiatry, 2014; PMID 24633934): neuropsychiatric symptoms and a trail-making test improved against placebo. One trial with manufacturer-affiliated authors, not independently repeated: C.
PMID 24633934
Dementia prevention in older adults
Grade D
GEM (DeKosky et al., JAMA, 2008; PMID 19017911): 3,069 adults aged 75 and over, 120 mg twice a day for a median 6.1 years; dementia 3.3 against 2.9 per 100 person-years (hazard ratio 1.12, 0.94 to 1.33), and no effect on progression in those who entered with mild cognitive impairment. GuidAge (Vellas et al., Lancet Neurol, 2012; PMID 22959217): 2,854 adults aged 70 and over with memory complaints, the same dose of EGb 761 for 5 years; probable Alzheimer's disease 1.2 against 1.4 per 100 person-years (hazard ratio 0.84, 0.60 to 1.18), in a trial funded by the extract's maker. Two large trials, neither preventing dementia: tested, no benefit. This does not grade symptoms in people who already have dementia, which are graded on their own rows.
PMID 19017911 PMID 22959217
Why Grade B and not Grade A
Grade B reflects moderate human evidence -- typically a single strong trial, multiple smaller trials, or surrogate endpoint data without hard clinical outcome replication. To reach Grade A, Ginkgo Biloba (EGb 761) would require at least one additional independent randomized trial demonstrating a hard clinical endpoint or objectively measured functional outcome in a comparable population.
What would move this grade
An independent randomized trial demonstrating a hard clinical endpoint -- mortality, major adverse event, or objectively confirmed functional improvement -- in an adequately powered sample, with results independently replicated, would support Grade A.
How to track whether this is working
A validated cognitive assessment (MoCA or ADAS-Cog) at baseline and after 12 weeks to measure the memory and attention outcomes studied in the EGb 761 trials. Subjective cognitive complaints using a standardized self-report scale alongside the objective test. EGb 761 is the specific extract studied: results with other ginkgo preparations are not established.