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Ginkgo biloba
EGb 761 (24% flavone glycosides + 6% terpene lactones) | Tebonin / Tanakan / maidenhair tree
Aliases (13)
Overview
What is Ginkgo biloba?
Ginkgo biloba is a standardized leaf extract from the maidenhair tree — a 270-million-year-old 'living fossil' species. The clinical-grade extract EGb 761 (Schwabe Pharmaceuticals, Germany — registered Rx as Tebonin) is standardized to 24% flavone glycosides + 6% terpene lactones (ginkgolides A/B/C/J + bilobalide) with <5 ppm ginkgolic acids. OTC dietary supplement in the US; prescription drug in Germany, France (Tanakan), and parts of Asia for cognitive impairment, vertigo, and tinnitus of vascular origin. Not WADA-banned.
Key Benefits
Modest cerebrovascular vasodilation, hemorheology improvement, free-radical scavenging, and platelet-activating-factor (PAF) antagonism. Strongest evidence in mild-to-moderate dementia, vertigo of vascular origin, and intermittent claudication. Largely null in healthy adults and in dementia prevention. Cleaner-evidenced cognitive enhancers (citicoline, bacopa, ALCAR) cover the cognitive axis without Ginkgo's bleeding-risk profile.
Mechanism of Action
Cerebrovascular and peripheral vasodilation via NO-mediated endothelial relaxation + reduced blood viscosity. Vessel-state-dependent — minimal effect in healthy young vasculature, more pronounced where flow is impaired.
Pharmacokinetics
Research Indications
1. Hemorheology and cerebrovascular flow
Flavone glycosides (kaempferol, quercetin, isorhamnetin) and terpene lactones together produce increased cerebral blood flow via three su…
2. Platelet-activating-factor (PAF) antagonism — the bleeding-risk axis
Ginkgolide B is a potent PAF antagonist (PAF = 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine; an inflammatory lipid mediator that trigge…
3. Antioxidant + mitochondrial protection
Flavone glycosides are direct free-radical scavengers (singlet oxygen, hydroxyl radical, peroxyl radical). Bilobalide (the sesquiterpene …
4. Modest neuromodulation
At higher doses (240+ mg/day), Ginkgo shows: - Modest MAO-A and MAO-B inhibition (in vitro and animal data; clinical magnitude in humans …
Research Protocols
Disclaimer: These are commonly discussed research protocols and not medical advice.
Peptide Interactions
✅ Different mechanisms (cholinergic substrate vs cerebrovascular flow + antioxidant). Rationale for stacking exists in dementia / vascular cognitive impairme…
✅ Both target cerebrovascular flow (vinpocetine via PDE1 inhibition + Na+ channel blockade); commonly co-formulated in old-school nootropic stacks. Both shar…
✅ Mechanistically orthogonal (BDNF + cholinergic vs flow + PAF). Plausible stack for cognitive-aging users; not particularly compelling for healthy young adu…
✅ Mostly orthogonal; both are botanical adaptogens with cardiovascular and cognitive signals. Stack-safe.
⚠ Mechanistically clean (different pathways) but omega-3 has a mild antiplatelet effect of its own; combined antiplatelet load increases. Manageable at stand…
❌ Multiple case reports of bleeding (intracerebral, subdural, GI). Contraindicated in routine practice.
❌ Additive antiplatelet via PAF mechanism distinct from COX-1 / P2Y12. Bleeding risk meaningfully elevated.
❌ Same logic as aspirin.
❌ Additive bleeding risk; case reports exist.
❌ Additive antiplatelet + GI bleeding risk. Particularly relevant for an MMA athlete using ibuprofen post-training — the most common real-world problematic c…
❌ SSRIs reduce platelet serotonin uptake → mild antiplatelet effect of their own. Combined with Ginkgo, bleeding risk rises (case reports of GI bleed, easy b…
⚠ Theoretical additive MAO inhibition; clinical signal weak but flagged.
Quality Indicators
EGb 761 standardization (24/6 ratio)
Look for explicit '24% flavone glycosides + 6% terpene lactones' on the label — the standardization used in essentially every positive clinical trial.
<5 ppm ginkgolic acids spec
Quality extracts publish ginkgolic acid content <5 ppm. Higher levels are linked to allergic skin reactions and rare hepatotoxicity case reports.
Third-party CoA + GMP certification
Reputable brands publish a Certificate of Analysis for identity, potency, ginkgolic acid content, heavy metals, and microbial contaminants.
Generic 'Ginkgo biloba' without 24/6 standardization
Whole-leaf or non-standardized capsules may not replicate even the modest signals of clinical-trial extracts. The active fraction varies seasonally and by source.
No origin / no ginkgolic acid spec
Unbranded or no-CoA capsules from anonymous sellers carry adulteration and ginkgolic acid contamination risk.
Contains seeds / 'whole-plant'
Ginkgo seeds contain ginkgotoxin (4'-O-methylpyridoxine) — neurotoxic and seizure-triggering. Only leaf extracts should be used.
What to Expect
- Onsettypically nothing acute. Some users report a mild peripheral warmth (hand/foot warming) within days — consistent with mild peripheral vasodilation. Cognitiv…
- Week 1-2generally nothing felt. Some users report mild lightheadedness or slight headache (likely mild vasodilation in cerebral vessels).
- Week 4-8subset of users (especially older or those with subclinical vascular issues) report subjectively "clearer head," better word retrieval, less mental fog. You…
- Week 8-12plateau of any subjective effect.
Side Effects & Safety 6
Side Effects
- 1Mild headache — typically resolves within first 1-2 weeks. Likely mild cerebral vasodilation.
- 2GI upset (nausea, dyspepsia, loose stools) — most common at >240 mg/day or empty-stomach dosing. Resolves with food.
- 3Lightheadedness / dizziness — typically dose-related; reduce to 120 mg if persistent.
- 4Easy bruising / prolonged bleeding from minor cuts — the dose-dependent PAF-antagonist signal. Reduce dose or discontinue if persistent.
- 5Allergic skin reactions — usually traced to ginkgolic acid contamination >5 ppm in poorly-standardized products. Use only certified <5 ppm extracts (EGb 761 standard).
- 6Palpitations — uncommon; occasionally reported, possibly via mild MAO inhibition.
When to Stop
- Spontaneous bleeding events — case reports of:
- Spontaneous intracerebral hemorrhage (Rowin 1996, *Neurology* — first major case report)
- Subdural hematoma (Rosenblatt 1997)
- Spontaneous hyphema (anterior chamber bleed; Rosenblatt 1997)
- Post-surgical bleeding (multiple case reports across orthopedic, neurosurgical, dental contexts)
- GI bleeding when stacked with NSAIDs
- Seizure threshold lowering — animal data and case reports suggest Ginkgo can lower seizure threshold (especially in poorly-standardized products with elevated ginkgotoxin / 4'-O-methylpyridoxine — found mostly in seeds, but trace amounts in some leaf preparations). Hard-block in seizure history.
- Hepatotoxicity — very rare; isolated case reports, usually with confounding products or hepatic insults.
- Stevens-Johnson syndrome / severe cutaneous reaction — extremely rare; almost exclusively in ginkgolic-acid-contaminated products.
- First 2 weeks: GI tolerance, headache, dizziness. Most common discontinuation period.
- Week 4-8: any new bleeding signs (gum bleeds, nosebleeds, easy bruising) — reassess dose and concurrent medications.
- Pre-surgical / dental window (any time): discontinue ≥7 days. Critical for any planned procedure.
- Combat-sport context: factor in head-impact bleeding risk during sparring blocks. Personal call, but a strong reason to avoid Ginkgo during heavy sparring camps.
References
Snitz et al. 2009 — *JAMA* — GEM Study cognitive decline analysis (PMID 20048210)
definitive 8-year null on cognitive decline in elderly.
View StudyDeKosky et al. 2008 — *JAMA* — GEM Study primary outcome dementia incidence (PMID 19017911)
definitive null on dementia prevention.
View StudySolomon et al. 2002 — *JAMA* — Ginkgo for memory in healthy adults (PMID 12190360)
first major rigorous null in healthy adults.
View StudyLe Bars et al. 1997 — *JAMA* — Ginkgo for AD / multi-infarct dementia (PMID 9343463)
foundational positive dementia trial.
View StudyBirks & Grimley Evans 2009 — *Cochrane Database Syst Rev* — Ginkgo for cognitive impairment / dementia (PMID 19160216)
canonical "inconsistent and unconvincing" Cochrane verdict.
View StudyVellas et al. 2012 (GuidAge) — *Lancet Neurol* — 5-year Ginkgo for AD prevention
second-largest prevention trial; null.
View StudyPittler & Ernst 2000 — *Am J Med* — Cochrane meta-analysis Ginkgo for intermittent claudication
modest peripheral arterial signal.
View StudyHilton et al. 2013 — *Cochrane Database Syst Rev* — Ginkgo for tinnitus
no benefit in primary tinnitus.
View StudyRowin & Lewis 1996 — *Neurology* — spontaneous bilateral subdural hematomas on Ginkgo
first major bleeding case report.
View StudyNootropics Expert — Ginkgo biloba profile
community-facing dosing + subjective synthesis.
View StudyEMA Tebonin (EGb 761) summary of product characteristics — German registration
clinical product reference.
View StudyHow was your experience with this compound?
Anonymous · one vote per session · results below at 5+ votes.
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