Evidence Level
Moderate
4 Clinical Trials
6 Documented Benefits
3/5 Evidence Score

Ginkgo biloba is a popular herbal supplement derived from the leaves of the Ginkgo tree, one of the oldest living tree species. It is commonly used to support cognitive function, memory, and circulation. Rich in antioxidants like flavonoids and terpenoids, Ginkgo may help improve blood flow to the brain and protect cells from oxidative damage. It’s often taken for age-related cognitive decline, mental clarity, and sometimes for symptoms like tinnitus or anxiety. Clinical results vary widely by product: nearly all rigorous trials used the standardized extract EGb 761® (24% flavonol glycosides, 6% terpene lactones), and non-standardized ginkgo products may not contain comparable levels of active compounds.

Studied Dose 120–240 mg/day standardized leaf extract (24% flavonol glycosides, 6% terpene lactones), in 1–2 divided doses; the most rigorously studied form is the standardized EGb 761® extract
Active Compound Standardized leaf extract (~24% flavonol glycosides, ~6% terpene lactones): flavonoids (quercetin, kaempferol, isorhamnetin) and terpene lactones (ginkgolides A/B/C, bilobalide)

Benefits

Cognitive Function and Memory

Ginkgo biloba is often promoted for enhancing memory and cognitive performance, particularly in older adults. Some studies suggest it may improve attention, memory, and processing speed in healthy individuals or those with mild cognitive impairment. For example, it’s thought to enhance cerebral blood flow, which may support brain function. Evidence for Alzheimer’s disease or dementia is mixed. Some trials show modest benefits in slowing cognitive decline, while others find no significant effect compared to placebo.

Circulation and Cardiovascular Health

Ginkgo may improve blood circulation by dilating blood vessels and reducing blood viscosity. This can potentially help with conditions like peripheral artery disease or intermittent claudication (leg pain due to poor blood flow), where studies have shown improved walking distance. It’s also used to alleviate symptoms of poor circulation, such as cold hands and feet.

Antioxidant Properties

Ginkgo contains flavonoids and terpenoids, which act as antioxidants, neutralizing free radicals and reducing oxidative stress. This may help protect cells from damage linked to aging, heart disease, and neurodegenerative conditions.

Anxiety and Mood

Some evidence suggests ginkgo may reduce symptoms of anxiety, particularly in older adults or those with generalized anxiety disorder. Its effects are likely tied to improved cerebral blood flow and antioxidant activity.

Tinnitus and Hearing

Ginkgo is sometimes used to treat tinnitus (ringing in the ears), with mixed results. Some studies report reduced severity, while others show no benefit. It may be more effective in cases linked to poor blood flow.

Eye Health

Ginkgo may benefit conditions like glaucoma or age-related macular degeneration by improving blood flow to the eyes and protecting retinal cells from oxidative damage. Limited studies show potential for preserving vision in these conditions.

Mechanism of action

1

Antioxidant Activity

Mechanism: Flavonoids in ginkgo act as free radical scavengers, neutralizing reactive oxygen species (ROS) and reducing oxidative stress. This protects cells, particularly neurons and vascular tissues, from damage linked to aging, neurodegenerative diseases, and cardiovascular issues. May mitigate cellular damage in conditions like dementia, heart disease, and retinal degeneration.

2

Improved Blood Flow and Vasodilation

Mechanism: Ginkgo enhances microcirculation by promoting vasodilation (via nitric oxide pathways) and reducing blood viscosity. Ginkgolides inhibit platelet-activating factor (PAF), which reduces platelet aggregation and prevents excessive blood clotting. Supports cerebral and peripheral blood flow, potentially aiding cognitive function, reducing symptoms of intermittent claudication, and improving eye health in conditions like glaucoma.

3

Neuroprotection

Mechanism: Ginkgo protects neurons by reducing oxidative damage, stabilizing mitochondrial function, and modulating neurotransmitter activity (e.g., enhancing cholinergic signaling). Bilobalide may inhibit excitotoxicity by regulating glutamate release. May slow cognitive decline in mild cognitive impairment or Alzheimer’s and support brain health under stress (e.g., hypoxia).

4

Anti-Inflammatory Effects

Mechanism: Ginkgolides, particularly ginkgolide B, inhibit PAF, a mediator of inflammation, reducing inflammatory responses in tissues. Flavonoids also suppress pro-inflammatory cytokines. May alleviate symptoms in conditions involving inflammation, such as tinnitus or cardiovascular diseases.

5

Modulation of Neurotransmitters

Mechanism: Ginkgo may influence serotonin, dopamine, and acetylcholine systems, potentially enhancing mood and cognitive processing. It may also inhibit monoamine oxidase (MAO), increasing neurotransmitter availability. Could contribute to reduced anxiety and improved cognitive performance, though evidence is preliminary.

6

Mitochondrial and Cellular Protection

Mechanism: Ginkgo stabilizes mitochondrial membranes and enhances energy production, protecting cells from apoptosis (programmed cell death) under stress. Supports neuronal and vascular health, potentially benefiting conditions like dementia and ischemia.

Clinical trials

1
Cochrane Review: Ginkgo for Cognitive Impairment & Dementia

Cochrane systematic review pooling 36 randomized, placebo-controlled trials of Ginkgo biloba extract (most using the standardized EGb 761® form) across cognitive impairment and dementia of varying severity.

36 trials; thousands of participants with cognitive impairment or dementia.

Concluded the evidence that Ginkgo biloba produces any predictable, clinically significant benefit for cognitive impairment or dementia is inconsistent and unreliable — the more recent, larger, better-designed trials were largely negative. Ginkgo was as safe as placebo.

2
Meta-Analysis: Ginkgo in Healthy Adults

Meta-analysis of placebo-controlled trials testing whether Ginkgo biloba enhances cognition in healthy people, pooling memory, executive function, and attention outcomes.

Healthy adults (1,132 / 534 / 910 participants across the three cognitive domains).

Effect sizes were essentially zero and non-significant across memory, executive function, and attention. Concluded ginkgo has no ascertainable cognitive-enhancing effect in healthy individuals — does not support 'memory booster' marketing for people without cognitive impairment.

3
Cochrane Review: Ginkgo for Intermittent Claudication

Cochrane systematic review of 14 randomized placebo-controlled trials of Ginkgo biloba for intermittent claudication (leg pain from peripheral arterial disease), assessing pain-free walking distance.

14 trials, 739 participants with peripheral arterial disease.

Ginkgo produced only a small, statistically non-significant increase in pain-free walking distance versus placebo, with no clinically meaningful benefit for intermittent claudication. Effectively a no-benefit conclusion for circulation symptoms at studied doses.

4
Cochrane Review: Ginkgo for Tinnitus

Cochrane systematic review evaluating Ginkgo biloba in adults whose primary complaint was tinnitus (ringing in the ears).

Adults with primary tinnitus across the included trials.

Found no evidence that Ginkgo biloba is effective when tinnitus is the primary complaint. A clearly negative review for the common 'ginkgo for ringing ears' use, though it may differ where tinnitus accompanies dementia.

Side effects and drug interactions

Common Potential side effects

Gastrointestinal: Nausea, upset stomach, diarrhea, or constipation.
Neurological: Headaches, dizziness, or vertigo, particularly at higher doses.
Allergic Reactions: Skin rash or itching in sensitive individuals.
Bleeding Risk: In rare cases, Ginkgo may inhibit platelet aggregation (due to ginkgolides), increasing the risk of bleeding, especially when combined with blood thinners (e.g., warfarin, aspirin) or NSAIDs. Rare cases of serious bleeding (e.g., intracranial hemorrhage) have been reported.
Seizures: In rare cases, ginkgo may lower the seizure threshold, particularly in individuals with epilepsy or those taking medications that affect seizure risk.
Allergic Reactions: Severe allergic reactions (e.g., anaphylaxis) are rare but possible.
Cardiovascular: Palpitations or increased heart rate in some users.
Psychiatric: Anxiety or restlessness, though uncommon, may occur, especially at high doses.

Important Drug interactions

Interactions: Ginkgo can interact with anticoagulants, antiplatelet drugs, SSRIs, or anticonvulsants, potentially increasing side effects or reducing drug efficacy.

Frequently asked questions about Ginkgo Biloba

How much ginkgo biloba should I take?

Studies typically use 120 to 240 mg per day of a standardized leaf extract such as EGb 761, split into two or three doses. The extract is standardized to about 24% flavone glycosides and 6% terpene lactones, so look for those figures on the label.

How long does ginkgo take to work?

Ginkgo is slow-acting; cognitive and circulation studies often run 8 to 12 weeks or longer. Plan on at least a couple of months of consistent use before judging effects on memory or mental sharpness.

Does ginkgo thin the blood?

Ginkgo can have a mild blood-thinning effect. If you take anticoagulants or antiplatelet drugs such as warfarin or aspirin, have a bleeding disorder, or are scheduled for surgery, talk to your doctor first and generally stop it about two weeks before any procedure.

What is ginkgo biloba good for?

Ginkgo is most popular for cognitive support, memory, and healthy circulation, and is also studied for age-related eye and ear concerns. Results in research are mixed, so view it as supportive rather than a guaranteed memory booster.

What is Ginkgo Biloba?

Ginkgo biloba is a popular herbal supplement derived from the leaves of the Ginkgo tree, one of the oldest living tree species. It is commonly used to support cognitive function, memory, and circulation.

References(4 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Birks J, Grimley Evans J. Ginkgo biloba for cognitive impairment and dementia. Cochrane Database Syst Rev. 2009;2009(1):CD003120. doi: 10.1002/14651858.CD003120.pub3.PubMedUsed to support: Benchmark Cochrane review (36 trials). Concluded the evidence that Ginkgo biloba has any predictable, clinically significant benefit for cognitive impairment or dementia is inconsistent and unreliable; the larger, better-designed trials were mostly negative. Ginkgo was as safe as placebo.
  2. Laws KR, Sweetnam H, Kondel TK. Is Ginkgo biloba a cognitive enhancer in healthy individuals? A meta-analysis. Hum Psychopharmacol. 2012;27(6):527-33. doi: 10.1002/hup.2259.PubMedUsed to support: Meta-analysis of ginkgo in healthy adults. Effect sizes across memory, executive function, and attention were essentially zero and non-significant — ginkgo has no ascertainable cognitive-enhancing effect in people without cognitive impairment.
  3. Nicolaï SP, Kruidenier LM, Bendermacher BL, Prins MH, Stokmans RA, Broos PP, Teijink JA. Ginkgo biloba for intermittent claudication. Cochrane Database Syst Rev. 2013;2013(6):CD006888. doi: 10.1002/14651858.CD006888.pub3.PubMedUsed to support: Cochrane review (14 trials, 739 participants). Ginkgo produced only a small, non-significant increase in pain-free walking distance versus placebo and no clinically meaningful benefit for intermittent claudication.
  4. Hilton MP, Zimmermann EF, Hunt WT. Ginkgo biloba for tinnitus. Cochrane Database Syst Rev. 2013;2013(3):CD003852. doi: 10.1002/14651858.CD003852.pub3.PubMedUsed to support: Cochrane review of ginkgo for tinnitus. Found no evidence that Ginkgo biloba is effective when tinnitus is the primary complaint — a negative review for the common 'ginkgo for ringing ears' claim.