Herb reference
Ginkgo biloba L.
Crystalis is a reference resource for herbal, crystal, and somatic practice.
This library is designed to help readers orient, compare, and research. It is not a substitute for medical care or practitioner judgment.
Botanical / meta
A large deciduous dioecious tree reaching 20–35 m in height, with distinctive fan-shaped (flabellate) leaves that turn bright yellow in autumn. The leaves have dichotomous venation — veins that fork repeatedly — a characteristic shared by few other plants. Female trees produce fleshy, plum-like seeds with a malodorous outer layer; male trees produce pollen cones.
Ginkgo leaf extract contains flavonoid glycosides (quercetin, kaempferol, isorhamnetin), terpene trilactones (ginkgolides A, B, C, J and bilobalide), and proanthocyanidins. Ginkgolides are unique to Ginkgo and are potent antagonists of platelet-activating factor (PAF). The standardized extract EGb761 (24% flavone glycosides, 6% terpene lactones) is the most extensively studied form and serves as the reference for clinical trials.
The practical read
Ginkgo leaf extract contains flavonoid glycosides (quercetin, kaempferol, isorhamnetin), terpene trilactones (ginkgolides A, B, C, J and bilobalide), and proanthocyanidins. Ginkgolides are unique to Ginkgo and are potent antagonists of platelet-activating factor (PAF). The standardized extract EGb761 (24% flavone glycosides, 6% terpene lactones) is the most extensively studied form and serves as the reference for clinical trials.
Route panel
Evidence and safety may differ by preparation. Essential oil, tea, tincture, extract, infused oil, and topical use are not interchangeable.
Quality
Extremely hardy and adaptable once established; tolerant of urban pollution, compacted soil, and pests. Prefers full sun and well-drained soil. Slow-growing for the first few years. Dioecious — male cultivars (e.g., 'Autumn Gold') are preferred for ornamental planting as female fruits are malodorous. Can live for centuries with minimal care.
Standardized leaf extract (EGb761) is the preferred form, standardized to 24% flavone glycosides and 6% terpene lactones. Leaf tea is not recommended as the terpene lactones are poorly water-soluble. Available as capsules, tablets, liquid extracts, and bulk dried leaf. Look for products standardized to known marker compounds. Avoid unprocessed raw seeds entirely.
Companion
Crystal side
The deeper layer
Clinical and compound notes are included as a research layer, not as treatment instructions.
HIGH RISK — CONTRAINDICATED WITH ANTICOAGULANT AND ANTIPLATELET MEDICATIONS (warfarin, aspirin, heparin, clopidogrel, dabigatran). Ginkgo has antiplatelet effects and significantly increases bleeding risk when combined with blood thinners. Discontinue at least 2 weeks before surgery or dental procedures. Use with extreme caution in individuals with bleeding disorders. Some reports suggest a possible seizure risk at very high doses, particularly in individuals with seizure disorders — avoid in epilepsy. May cause gastrointestinal upset, headache, dizziness, and allergic skin reactions. The raw seeds are toxic and contain ginkgotoxin (4'-O-methylpyridoxine), which can cause seizures — do NOT consume unprocessed seeds. The fleshy seed coat can cause severe contact dermatitis. Not recommended during pregnancy or breastfeeding due to insufficient safety data and antiplatelet effects. May interact with SSRIs and other serotonergic medications (rare reports of serotonin syndrome). Not recommended for children.
Questions
Ginkgo is high risk and contraindicated with anticoagulant and antiplatelet medications including warfarin, aspirin, heparin, clopidogrel, and dabigatran, because its ginkgolides antagonize platelet-activating factor and significantly increase bleeding risk when combined with blood thinners. It should be discontinued at least two weeks before surgery or dental procedures and used with extreme caution in anyone with a bleeding disorder. Raw ginkgo seeds are toxic and contain ginkgotoxin (4-O-methylpyridoxine), which can cause seizures, so unprocessed seeds must not be consumed, and the fleshy seed coat can cause severe contact dermatitis. Some reports suggest a possible seizure risk at very high doses, so ginkgo should be avoided in epilepsy, and there are rare reports of serotonin syndrome with SSRIs and other serotonergic drugs. It is not recommended in pregnancy, breastfeeding, or children.
Ginkgo is used as a concentrated, standardized leaf extract rather than as a simple leaf tea, because the therapeutic effects are tied to a defined extract composition. The reference preparation is EGb761, standardized to 24% flavone glycosides and 6% terpene lactones, which is the form used in most clinical trials. Standardization matters because both the flavonoid glycosides and the unique terpene trilactones, the ginkgolides and bilobalide, contribute to activity. A Cochrane review of ginkgo for cognitive impairment and dementia found the evidence inconsistent and unreliable for a clinically important benefit, so expectations should be measured. Crude leaf preparations are not equivalent to the standardized extract, and raw seeds must never be used.
For ginkgo, quality is defined less by the appearance of the leaf and more by standardization of the extract. A quality product should state standardization to roughly 24% flavone glycosides and 6% terpene lactones, matching the EGb761 reference, since unstandardized leaf or tea may contain little of the active terpene trilactones. Reputable products also limit ginkgolic acids, which are allergenic and irritant contaminants that good manufacturing reduces to low levels. Without a stated standardization, a ginkgo product's potency is essentially unknown. The terpene lactones, ginkgolides A, B, C, J and bilobalide, are unique to ginkgo and are the markers that matter most.
Ginkgo's most distinctive constituents are the terpene trilactones, the ginkgolides and bilobalide, which are found in no other plant. The ginkgolides, particularly ginkgolide B, are potent antagonists of platelet-activating factor, a signaling molecule involved in platelet clumping and inflammation. This anti-PAF activity is central to ginkgo's proposed circulatory effects but is also exactly why it increases bleeding risk and is contraindicated with anticoagulant and antiplatelet drugs. The flavonoid glycosides add antioxidant activity, but it is the ginkgolide-driven PAF antagonism that most defines ginkgo and underlies its main safety concern. This dual nature, distinctive chemistry paired with real bleeding risk, is the key to understanding the herb.
Store standardized ginkgo extract in its sealed container away from light, heat, and humidity, and use it within the labeled shelf life to maintain the flavonoid and terpene lactone content. Capsules and tablets generally hold potency well when kept cool and dry, while loose dried leaf degrades faster and is in any case not the preferred form. Moisture is the main enemy, since it can promote breakdown and microbial growth, so containers should be kept tightly closed. Because the active terpene trilactones cannot be judged by smell or appearance, observing the expiry date is the most reliable approach. Discard products past their labeled life rather than assuming continued potency.
Sources & Citations
Peer-reviewed sources for the pharmacological and clinical claims on this page. Crystalis herb entries describe tradition and current research; they are reference, not medical advice.
SCI
Resource framing
Crystalis is a reference resource for herbal, crystal, and somatic practice.
This library is designed to help readers orient, compare, and research. It is not a substitute for medical care or practitioner judgment.
Clinical and compound notes are included as a research layer, not as treatment instructions.
Evidence and safety may differ by preparation. Essential oil, tea, tincture, extract, infused oil, and topical use are not interchangeable.