Ginkgo biloba
Ginkgo biloba
Other names: Ginkgo
Fan-shaped leaves; leaf extracts in supplements.
Large two-lobed leaves on long petioles.
- Family
- Ginkgoaceae
- Plant type
- Tree
- Safety level (indicative)
- Caution
What the safety levels mean (expand legend)
- Generally recognised as safe. Often a common herb with reasonable harvest and use; still read the specific warnings on the card.
- Information. Primarily informational — details in the text and warnings below matter most.
- Caution. Needs extra care (dose, duration, sensitive groups, interactions).
- Risky. Significant risks — verify sources, contraindications and professional guidance.
- Not for home experimentation. Not suitable to experiment with at home without knowledge and certainty.
- High risk for internal use. Particular risk with internal use (e.g. alkaloids); avoid prolonged or irresponsible dosing.
- Not specified. Level not filled in yet — rely on individual warnings and links below.
Safety — read before use
For this herb it is important to check warnings, mix-ups and cautions. Start with the Safety section.
Quick overview
A practical summary; details are in the sections below.
- Safety grade
- Caution·details
- Scientific sources on the card
- Yes — sources are listed with claims·Science section
- When and what to harvest
- Leaf — June–September
- Processing methods
Herbal infusion (tea), Capsules
All methods and recipes on the card- Topics and symptoms
- No topic links yet.Topics section · Symptoms overview
Identification and mix-ups
Deciduous leaves of characteristic shape.
Possible mix-ups and risks
Young trees may resemble some broadleaves—leaf is decisive.
Similar herbs
No related herbs are linked yet.
Topics and symptoms
More topics are in the symptoms and topics overview.
No topic links are recorded yet.
Drug interactions and photosensitivity
Information on the card — not a substitute for professional medical care or individual assessment.
Drug interactions
Concomitant use with anticoagulants (e.g. phenprocoumon, warfarin) or antiplatelet drugs (clopidogrel, acetylsalicylic acid and other NSAIDs) may modify their effect — coagulation monitoring is advised when initiating, adjusting, or discontinuing Ginkgo. An interaction study with talinolol indicates that Ginkgo biloba may inhibit intestinal P-glycoprotein, potentially increasing exposure to P-gp-dependent drugs such as dabigatran etexilate — caution is advised. One interaction study has shown that nifedipine Cmax may increase up to twofold, with reports of dizziness and hot flushes. Concomitant use with efavirenz is not recommended — Ginkgo induces CYP3A4 and may decrease efavirenz plasma concentrations. Because Ginkgo may increase susceptibility to bleeding, preparations should be discontinued 3 to 4 days prior to planned surgery.
Sources
Geographic occurrence
Czechia
Common (expected wild occurrence in the region)
Wild occurrence or common cultivation / gardens in the Czech Republic depending on species.
Austria
Occasional (garden, cultivation, or fringe of the range)
Wave 1 (seed): often cultivation or border-range occurrence — refine per species and source.
Germany
Occasional (garden, cultivation, or fringe of the range)
Wave 1 (seed): often cultivation or border-range occurrence — refine per species and source.
Hungary
Occasional (garden, cultivation, or fringe of the range)
Wave 1 (seed): often cultivation or border-range occurrence — refine per species and source.
Poland
Occasional (garden, cultivation, or fringe of the range)
Wave 1 (seed): often cultivation or border-range occurrence — refine per species and source.
Slovakia
Occasional (garden, cultivation, or fringe of the range)
Wave 1 (seed): often cultivation or border-range occurrence — refine per species and source.
Japan
Common (expected wild occurrence in the region)
Japan top 20: temperate and East Asian context — verify Japanese flora and cultivation.
Harvest
- LeafJune–September
léto
Region: CzechiaNotes: Leaves before yellowing on mature trees — often from cultivation.
Storage
- Drying(Leaf)
Ginkgo leaf dried in paper.
- Light:
- Cool.
- Moisture:
- Damp.
- Safety:
- Drug interactions — see the herb page.
Processing methods on this herb card
Infusion or brief extraction in hot water; usually without long boiling.
Full method description (from the catalogue)
In the narrow sense, “tea” often means an infusion: you pour water just off the boil over the dried plant matter and let it steep for a few minutes. Temperature, steep time, and the herb-to-water ratio change both flavour and what dissolves into the liquid.
Compared with a decoction, heat exposure is shorter and gentler; tender leaves and flowers are often better as an infusion than with prolonged simmering. For each herb, always follow the plant card for suitable plant part, preparation, and safety notes — general rules never replace species-level judgement.
Traditional context for this method: yes·Scientific context for this method: no
Filling capsules with dried herb or powder; home and industrial variants.
Full method description (from the catalogue)
Capsules allow precise dosing and mask bitter tastes. Home fillers exist, but hygiene, blend uniformity, and storage are harder than with tea.
Follow supplement legislation where it applies.
Traditional context for this method: no·Scientific context for this method: yes
Traditional / spiritual use
Kept separate from science — entries are cultural or symbolic, not medical advice.
Related guides in the library
Traditional folk context
General
The herb appears in older folk customs referenced on Czech cards. This note is cultural memory and seasonal storytelling — not a dosing guide, clinical indication, or substitute for the safety section.
- Form:
- různé
- Claim strength:
- Tradition
- Source note:
- Cultural framing only.
Scientific notes
Each claim lists a study type and a source (URL or DOI) where available. Dose notes from the literature are informational only.
How to read evidence strength and study type labels
Labels summarise how the catalogue entry is tagged — they are not a medical verdict on efficacy. For every row, read the summary, limitations and source link.
Evidence strength
- Evidence level not specified
- The author did not grade the record; judge from the summary, limitations and source link.
- Narrative / orientational literature
- Descriptive or expert literature without controlled group comparison — context rather than proof of effect.
- Weak evidence
- Study or conclusion with major methodological limits; treat only as a pointer for further reading.
- Preliminary findings
- First or smaller studies — interesting direction, not the final word on efficacy or safety.
- Moderate strength of evidence
- Moderate strength by study design; sample and context limits still apply.
- Stronger evidence
- Stronger design or consistency of results within the study's stated limits.
- Review article
- A review summarises multiple sources; quality depends on review method and field.
Study type
- Narrative / expert text
- Expert text or overview without a classical study design.
- In vitro study
- Cell culture or test-tube experiment — does not show an effect in the body.
- Animal study
- Animal model — transfer to humans is not automatic.
- Observational study
- Observing groups without random treatment assignment; confounding is possible.
- Clinical trial
- Human clinical trial; sample size and control group matter.
- Randomised controlled trial
- Randomised controlled trials are among the stronger designs when well conducted.
- Review study
- A review aggregates multiple papers — quality depends on selection rules.
- Systematic review
- Systematic review with explicit search and selection methodology.
- Meta-analysis
- Statistical pooling of studies; outcome depends on input data and heterogeneity.
- Regulatory assessment / monograph (EMA, WHO…)
- Regulatory body summary for a herbal product — different context from a single RCT; often about products, not home tea.
- Expert monograph (herbal preparations)
- Structured literature summary for a plant or drug — quality depends on author and edition year.
Scientific literature discusses effects and safety; this entry is an overview and does not replace professional care.
Evidence level not specifiedNarrative / expert textLimitations: Catalog seed — specific studies to be added based on content.
The EMA HMPC monograph for ginkgo leaf; the document primarily addresses extracts and powder in preparations, not a home leaf infusion.
Review articleRegulatory assessment / monograph (EMA, WHO…)Year: 2014Preparation form in the study: infusion
Active compound / focus: flavonoids, ginkgolides (per the document)
Limitations: Interactions and bleeding risks in the document primarily relate to medicinal preparations from the leaf.
Dose note (from literature): See the PDF for preparations.
EMA Committee on Herbal Medicinal Products (HMPC) — European Medicines Agency
Images
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Safety
What the warning types mean
The type on each warning helps group themes — it does not replace the separate severity badge.
- Internal use
- Risks from swallowing, extracts, duration of use or concentration for internal use.
- Interactions / medicines
- Possible effect on medicines or concurrent treatment — check sources and a professional.
- Raw plant parts
- Raw, unripe or poorly prepared plant parts can be dangerous.
- Toxins and regulation
- Toxic constituents or regulated compounds (e.g. in distillates).
- Contact with the plant
- Skin or mucosa irritation from contact with fresh plant or sap.
- Allergy
- Allergic reactions, often linked to family sensitisation.
- Harvesting and contamination
- Contamination, species mix-ups or harvesting from unsuitable places.
- Blood-thinning medications and anticoagulantsModerate severityInteractions / medicines
Ginkgo leaf may interact with certain medications (blood thinners, antiepileptics, and others) — consult a physician if you are taking such products.