Ginkgo biloba

Mechanism of action

Proposed mechanisms (not all definitively confirmed in humans): (1) antioxidant action and scavenging of reactive oxygen species; (2) modulation of endothelial function and microcirculation (possible improvement in tissue perfusion); (3) anti-inflammatory effects and modulation of neuronal signaling pathways; (4) antagonism of PAF (platelet-activating factor) attributed to ginkgolides, with potential impact on platelet aggregation and vascular tone; (5) effects on neurotransmission (cholinergic, monoaminergic) and synaptic plasticity reported in preclinical models. Clinical relevance varies and may be influenced by dose, standardization, and the subject’s baseline status.

Supported benefits

• Modest improvement in some cognitive domains (memory/attention) in older adults and/or in the presence of mild cognitive decline or dementia, especially with standardized extracts and treatments lasting weeks to months (moderate)
• Reduction of symptoms associated with cerebrovascular insufficiency/vertigo and some subjective disorders (variable outcomes across studies) (limited)
• Support for mild anxiety symptoms (some RCTs show reductions, but heterogeneity and risk of bias remain) (limited)
• Prevention of cognitive decline or dementia in the general population (prevention studies with often null or inconclusive results) (limited)
• Improvement in cognitive performance in young/healthy subjects (small and inconsistent effects) (emerging)

Safety & side effects

• Gastrointestinal disturbances (nausea, dyspepsia, diarrhea)
• Headache, dizziness
• Insomnia or restlessness in some subjects
• Skin/allergic reactions (more likely with low-quality products or contaminants)
• Abnormal bleeding: a rare but clinically relevant event, especially in the presence of risk factors or concomitant medications

FAQ

Does Ginkgo biloba improve memory in healthy subjects?

Evidence in young/healthy subjects is inconsistent: some studies report small improvements in specific tests, while others show no differences. When present, the effects tend to be modest and depend on dose, duration, and extract standardization.

How important is extract standardization?

Very important. The most cited clinical studies use standardized extracts with a defined profile of flavonoids and terpene lactones and low ginkgolic acids. Non-standardized products may have unpredictable efficacy and a worse safety profile.

Is it true that it increases the risk of bleeding?

There is biological plausibility (PAF antagonism) and clinical reports, especially in combination with drugs that affect coagulation/platelet aggregation. The absolute risk is generally low, but it can become relevant in predisposed subjects or with concomitant therapy.

How long does it take to notice any effects?

In studies on cognition/decline, when benefits are observed, they often emerge after several weeks of continuous use. Acute effects on focus are less predictable.

Is Ginkgo useful for tinnitus or vertigo?

Overall results are inconclusive and depend on the cause of the symptom and the protocol. In some vestibular conditions, improvements have been reported, but this is not a consistent outcome across studies.