Ginkgo Biloba for Cognitive Improvement
Ginkgo biloba should not be routinely recommended for cognitive improvement, as the evidence is inconsistent and unconvincing, with no predictable or clinically significant benefit demonstrated for dementia or cognitive impairment. 1
Evidence Quality and Recommendations
Insufficient Evidence for Cognitive Enhancement
Multiple high-quality guidelines classify ginkgo biloba as having insufficient evidence for cognitive improvement. The ASCO/SIO guidelines (2018) explicitly list ginkgo biloba under therapies with insufficient evidence to form a clinical recommendation for cognition. 2
The most comprehensive Cochrane systematic review (2007) concluded that evidence for ginkgo's benefit in dementia or cognitive impairment is "inconsistent and unconvincing." This review analyzed multiple randomized controlled trials and found that while some early small trials suggested benefit, the evidence does not support predictable clinical benefit. 1
A 2012 systematic review update identified two additional large randomized controlled trials (totaling 3,187 patients) that provided no reason to change the Cochrane Collaboration's negative conclusions. There remains no convincing evidence that ginkgo is effective for cognitive impairment or dementia. 3
Specific Findings on Cognitive Outcomes
Short-term cognitive benefits (at 12 weeks) showed some statistical improvement with ginkgo at any dose (SMD -0.65,95% CI -1.22 to -0.09, P=0.02), but these benefits did not persist at 24 weeks. 1
The evidence base suffers from methodological limitations including small sample sizes, unsatisfactory methods in early trials, and potential publication bias. 1, 4
Safety Considerations and Drug Interactions
Bleeding Risk
Ginkgo biloba contains ginkgolide B, which displaces platelet-activating factor from binding sites and decreases coagulation, creating bleeding risk. 5, 6
Multiple authoritative guidelines, including the American Academy of Neurology and American Academy of Family Physicians, specifically warn against combining ginkgo with medications affecting coagulation. 6
Patients with pre-existing bleeding disorders or those taking anticoagulants/antiplatelet drugs are at particularly high risk for adverse bleeding events. 5, 6
As a general precaution, ginkgo should be withdrawn two weeks before elective surgery due to bleeding risk. 3
Drug Interactions
Ginkgo may alter drug pharmacokinetics through inhibition of the cytochrome P450 system, potentially affecting metabolism of other medications. 5
Possible interactions have been reported with monoamine oxidase inhibitors, alprazolam, haloperidol, warfarin, and nifedipine. 7
Limited Evidence in Specific Contexts
Cisplatin-Induced Ototoxicity
- One small randomized trial (n=15 adults) showed improved hearing with ginkgo biloba extract (p=0.03) for cisplatin-induced ototoxicity, but this study had significant methodological concerns. The Lancet Child and Adolescent Health guideline (2020) did not generate recommendations based on this single small study. 2
Peripheral Arterial Disease
- For intermittent claudication, systematic review of 8 trials showed patients receiving 120-160mg daily for 12-24 weeks had a weighted mean difference in pain-free walking distance of 34 meters compared to placebo. However, outcomes are likely of marginal clinical importance. 5
Clinical Bottom Line
Do not recommend ginkgo biloba for cognitive improvement in clinical practice. The evidence does not support its use, and the bleeding risks, particularly in patients on anticoagulants or with bleeding disorders, outweigh any unproven cognitive benefits. 1, 3
For patients seeking cognitive support, consider FDA-approved medications for cognitive enhancement rather than ginkgo biloba. 6