Nuts & Seeds · Nut
Ginkgo Nuts
Ginkgo biloba · also called Ginkgo seed, bai guo, ginnan
Ginkgo nuts are the seed kernels of the ginkgo tree, eaten cooked in soups and desserts in parts of East Asia. They are starchy and low in fat, with copper and B vitamins. No study shows a health benefit from eating them. The most important caution is that the seeds contain a toxin that can cause seizures, mostly in children, and cooking does not remove it. This page is about the nut, not the leaf supplement.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Ginkgo Nuts
Ginkgo nuts are a cooked food in parts of East Asia. They carry a toxin that can cause seizures, so the main message is about caution, not benefit.
What it is
Ginkgo nuts are the kernels of seeds from the ginkgo tree (Ginkgo biloba), an ornamental tree that originated in China. They are eaten cooked in soups, desserts and side dishes, and also sold dried or pre-cooked.
USDA data for the dried item: 348 kcal per 100 g, with 10.35 g protein, 72.45 g carbohydrate and 2.0 g fat. A typical 1 ounce (28.35 g) portion is about 99 kcal. Per 100 g it has 0.536 mg copper, 0.43 mg thiamin, 11.7 mg niacin, 0.641 mg vitamin B6 and 998 mg potassium. Raw nuts have 182 kcal per 100 g. USDA lists no fibre for this food.
What the research shows
No trial or population study of eating ginkgo nuts for health was found. What exists is poisoning reports, laboratory-style reviews of the seed's chemistry and food-safety statements from authorities.
In case reports, people had high levels of the seed toxin and low levels of the active form of vitamin B6 in the blood. Doctors gave the active form in hospital and symptoms improved.
The ginkgo research on memory and blood flow is about a leaf extract supplement, which is a different product.
Nut versus leaf extract
Ginkgo leaf extract, the supplement, is a different product from the nut. NCCIH calls the extract likely safe for most adults in moderate amounts, and says fresh seeds are toxic and roasted seeds have caused serious side effects.
Amounts
This page gives no amounts to eat. No safe amount has been set. Ask a doctor, pharmacist or paediatrician, especially before giving ginkgo nuts to a child.
At a glance
Traditional uses history, not proof
- Eaten cooked in East Asian soups, desserts and side dishes
- Sold dried, canned or vacuum-packed as pre-cooked kernels
Studied for research
- Nutrients: copper, B vitamins and starch, composition only, no trial
- Memory and circulation: leaf extract research only, not the nut, insufficient evidence for the nut
- Safety: seizure poisoning, documented risk in case reports and by food authorities
Main compounds
- Ginkgotoxin (4'-O-methylpyridoxine), the main seed toxin
- Cyanogenic glycosides
- Ginkgolic acids (skin allergy, in the fleshy coat and tree)
- An allergic glycoprotein (review)
Common forms
- Cooked or roasted shelled kernels
- Dried kernels
- Canned or vacuum-packed pre-cooked kernels
- Raw or unripe seeds (reported to be more toxic)
- Leaf extract (a different product, not covered)
Research links: Hong Kong Centre for Food Safety: Ginkgo Seed Poisoning (2023) · NCCIH: Ginkgo · Systematic review: safety of 21 medicinal and edible seeds (2026) · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Ginkgo biloba
- Naming authority
- L.
- Common names
- Ginkgo nut (English); Ginkgo seed (English); Maidenhair tree seed (English); Bai guo (Chinese (pinyin)); Ginnan (Japanese)
- Family or group
- Not verified from a source read.
- Classification
- Plantae > not verified > not verified > not verified > Ginkgoaceae (not verified from a source read) > Ginkgo > Ginkgo biloba
- Native range
- Cutis 2022 abstract: the tree originated in China and is now grown worldwide as an ornamental tree.
- Habitat
- Not verified.
- What it looks like
- Roots: Not verified.; Stems: Not verified.; Leaves: Not verified.; Flowers: Not verified.; Fruit: The edible part is the seed kernel inside a shell, wrapped in a fleshy outer coat (the sarcotesta), which is the part blamed for skin reactions. This description relies on the report titles and general knowledge, not a source read in full.
- Cultivation
- Not verified.
- Harvest and processing
- Kernels are cooked (boiled, roasted or simmered), dried, or sold pre-cooked in cans and packs (existing summary).
- Look-alikes and adulterants
- Name: Ginkgo leaf extract (supplement); Note: Same tree, different part and product. Safety and evidence for the leaf extract do not describe the nut. See the ginkgo herb page.
- Sustainability and conservation
- Not assessed.
Photographs
Traditional use and history history, not clinical proof
| Tradition or era | Documented use | Source |
|---|---|---|
| East Asian cooking | Ginkgo seeds are commonly used in dishes in mainland China, Korea and Japan (Hong Kong Centre for Food Safety). | s-cfs-hk-204 |
| Traditional Chinese use | The Cutis abstract says the leaf extract has long been used in Chinese traditional medicine. Older history of the nut itself was not found in a source read. | p36179233 |
Traditional use shows how it was used. It does not show that it works or is safe today.
What is inside, and how it may work
What it contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.
Main compounds
| Compound | Family | Where it is concentrated | Activity studied | Level of evidence |
|---|---|---|---|---|
| Ginkgotoxin (4'-O-methylpyridoxine, MPN) | vitamin B6 look-alike | Seed storage tissue Not found. | Believed to be the main cause of seed poisoning. It resembles vitamin B6 and interferes with its biosynthesis, metabolism and function, including making the calming chemical GABA. Heat-stable. 12 8 | Human data |
| Ginkgotoxin glucoside | vitamin B6 look-alike | Seed Not found. | Named with MPN as a poisoning source in the reviews read. 8 3 | Review |
| Ginkgolic acids | alkylphenols | Tree and fleshy outer coat Not found. | Blamed for allergic contact dermatitis and described as cell-damaging in a processing review. 2 3 | Review |
| Allergic glycoprotein | protein | Seed Not found. | A processing review lists nausea, seizures, breathing trouble, vomiting and stomach ache as effects attributed to it. The abstract gives no figures. 3 | Review |
| Cyanogenic glycosides (amygdalin-derived) | cyanogenic glycoside | Seed Not found. | Named in the Hong Kong article and the processing review. Cooking may reduce them. 12 3 | Review |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Vitamin B6 activation and GABA | Not specified | In case reports, blood tests showed high toxin and low active vitamin B6 (PLP), and a lower PLP-to-pyridoxal ratio in blood and spinal fluid. The toxin is thought to lower GABA and raise glutamate, which are thought to cause seizures. Labelled human case-report and regulator statements. 10 1 9 12 | Human data |
Absorption, metabolism and elimination
- Absorption
- Symptoms started 1 to 12 hours after eating (Hong Kong authorities); onset was 7 to 9.5 hours in the cases read.
- Distribution
- The toxin was found in serum and spinal fluid in one child.
- Metabolism
- Toxin blocks the change of B6 forms into PLP (case reports).
- Elimination
- Not found.
- Bioavailability
- Not found.
Isolated compounds versus whole extracts
Ginkgo leaf extract (the supplement) and ginkgo nuts are different products. The extract is made from leaves and is judged likely safe for most adults in moderate amounts by NCCIH; the fresh and roasted seeds are toxic. Research on one does not describe the other.
Nutritional composition
Dried ginkgo nuts, per 100 g (USDA FoodData Central item 170175): 348 kcal, 10.35 g protein, 72.45 g carbohydrate, 2.0 g fat, 998 mg potassium, 0.536 mg copper, 0.43 mg thiamin, 11.7 mg niacin and 0.641 mg vitamin B6. USDA's household portion is 1 ounce (28.35 g), about 99 kcal. Raw nuts (item 170584) are lower in energy, 182 kcal per 100 g. USDA lists no fibre, vitamin E or selenium for this food. The vitamin B6 in the nut does not offset its toxin. Values vary with preparation, and canned or cooked kernels contain more water.
2 not enough evidence
What was looked at
The 2 benefits and uses checked for Ginkgo Nuts, each with how strong the evidence is. Tap one to open it.
- Copper, B vitamins and starch as a foodNot enough evidence
- Memory and circulation (this is leaf extract research, not the nut)Not enough evidence
Lab markers tracked in the studies
Ginkgotoxin (4'-O-methylpyridoxine) in bloodActive vitamin B6 (pyridoxal phosphate, PLP) in blood
What is Ginkgo Nuts good for?
There is no human trial of ginkgo nuts as a food for any health benefit. The two rows below explain what is and is not known.
Benefits, one by one
Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.
Copper, B vitamins and starch as a food
Not enough evidenceDried ginkgo nuts are a starchy, low-fat food that USDA lists as rich in copper, thiamin, niacin and vitamin B6. No study has tested whether eating them improves any health outcome.
2 studiesCooked, dried or canned kernels as food. Raw seeds are described as m…
Studies, doses and limits
What the trials found
No human study of eating ginkgo nuts for a health benefit was found. USDA FoodData Central lists, per 100 g of the dried item, 0.536 mg copper, 0.43 mg thiamin, 11.7 mg niacin and 0.641 mg vitamin B6.
Results
Nutrient content only. The B6 in the food does not protect against the seed toxin, which interferes with how vitamin B6 is used (see the Safety tab).
Effect sizes as reported
Dried, per 100 g: 348 kcal, protein 10.35 g, carbohydrate 72.45 g, fat 2.0 g, potassium 998 mg, copper 0.536 mg (USDA, summary-only).
Why this rating
Nutrient content is a listing, not evidence of benefit. No trial, cohort or review of ginkgo nut intake and health was found.
Form and dose studied
Cooked, dried or canned kernels as food. Raw seeds are described as more toxic.
Who was studied
Not studied.
Limits
USDA values were not re-opened on 2026-10-26 (service rate-limited). Nutrient values vary with how the nuts are prepared.
Why researchers looked
This is a composition fact, not a trial question. Ginkgo nuts are eaten as a food in East Asian cooking.
Traditional use
Cooked kernels are eaten in soups, desserts and side dishes in parts of East Asia (used here as a description of use, not as proof of benefit).
Proposed mechanism Composition data
Not applicable. These are nutrients present in the food.
A proposed mechanism does not show that the effect happens in people.
Not a safe food in large amounts. Read the Safety tab before eating ginkgo nuts, especially for children.
Memory and circulation (this is leaf extract research, not the nut)
Not enough evidenceMost ginkgo research on memory and blood flow used a leaf extract made in a factory. That research does not tell us anything about eating the nut.
1 studiesNot applicable.
Studies, doses and limits
What the trials found
NCCIH describes ginkgo leaf extract as likely safe for most adults in moderate amounts, and says fresh seeds are toxic and roasted seeds have caused serious side effects. The nut and the leaf extract are different products. See the ginkgo herb page for the leaf extract.
Results
No result for the nut. This entry is here only to separate the two products.
Why this rating
No study of the nut for memory or circulation was found; leaf extract results do not carry over.
Limits
Leaf extract research was not reviewed on this page.
Why researchers looked
The ginkgo name is famous for the leaf supplement, so people often assume the nut shares its benefits.
Proposed mechanism Unknown
Not established for the nut.
A proposed mechanism does not show that the effect happens in people.
Leaf extract has its own cautions (for example with blood thinners); those are covered on the ginkgo herb page.
Connections to the rest of health
How Ginkgo Nuts connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.
Explore every connection: goals, body systems, organs, symptoms, genes
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Nervous System | Biological association | Not enough evidence | Studied for: Memory and circulation (this is leaf extract research, not the nut) | 14 |
C. Body parts and organs
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Skin | Adverse effect or risk | Documented risk | Allergic contact dermatitis attributed to ginkgolic acids. Contact with the tree or fleshy seed coat can cause allergic dermatitis. Preparation or compound: Contact with the tree or fleshy seed coat |
2 6 |
E. Health conditions
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Ginkgotoxin (4'-O-methylpyridoxine) in blood | Biological association | Low certainty | Measured in trials: raised. A lab change is not the same as a health benefit. | 7 9 |
| Active vitamin B6 (pyridoxal phosphate, PLP) in blood | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 9 10 |
K. Biological pathways
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Ginkgotoxin (4'-O-methylpyridoxine, MPN) | Biological association | Human | Believed to be the main cause of seed poisoning. It resembles vitamin B6 and interferes with its biosynthesis, metabolism and function, including making the calming chemical GABA. Heat-stable. Preparation or compound: Seed storage tissue |
12 8 |
| Ginkgotoxin glucoside | Biological association | Review | Named with MPN as a poisoning source in the reviews read. Preparation or compound: Seed |
8 3 |
| Ginkgolic acids | Biological association | Review | Blamed for allergic contact dermatitis and described as cell-damaging in a processing review. Preparation or compound: Tree and fleshy outer coat |
2 3 |
| Allergic glycoprotein | Biological association | Review | A processing review lists nausea, seizures, breathing trouble, vomiting and stomach ache as effects attributed to it. The abstract gives no figures. Preparation or compound: Seed |
3 |
| Cyanogenic glycosides (amygdalin-derived) | Biological association | Review | Named in the Hong Kong article and the processing review. Cooking may reduce them. Preparation or compound: Seed |
12 3 |
Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 26, 2026).
Evidence at a glance: what changed in 2 lab markers
Tap a number to show only those markers. Counts are markers, not people.
The evidence
The research centre for Ginkgo Nuts. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.
Evidence by outcome
Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).
How we rate evidence
High certainty
Several well-run trials or reviews agree; further research is unlikely to change the picture much.
Moderate certainty
Good trials point the same way, but some doubt remains.
Low certainty
Small, short or inconsistent trials. The finding could change with better research.
Very low certainty
Very little or very weak human data. Treat as a possibility only.
Mixed findings
Trials or reviews disagree with each other.
Not enough evidence
Not enough human research to say either way.
Evidence against
Good research found no benefit, or found harm.
We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We started from our existing ginkgo nut summary, read two Hong Kong government pages and the NIH ginkgo page, and checked case reports and reviews on PubMed. Only abstracts were read for studies. Little research exists on the nut as a food, so this page is short on purpose.
Study library: every study we checked 16
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Azuma 2020 An Adult Case of Generalized Convulsions Caused by the Ingestion of Ginkgo biloba Seeds with Alcohol. Intern Med · PMID 32132337 · DOI |
Case report |
1 woman aged 64 years | Vomiting and tonic-clonic convulsions 9.5 hours after eating. Pyridoxal phosphate into a vein improved symptoms. Toxin and several B6 forms were high but active PLP was low. The authors say alcohol may have delayed the start of poisoning. One patient Methods, limits and fundingOutcomes: Symptoms, blood levels Limitations: One case; alcohol also taken. Funding and conflicts: Authors declared no conflicts of interest. Read: abstract | |
| Barker 2022 Botanical Briefs: Ginkgo (Ginkgo biloba). Cutis · PMID 36179233 · DOI |
Narrative review |
Skin reactions to the ginkgo tree | Contact with the ginkgo tree can cause allergic contact dermatitis (red bumps, blisters, swelling) attributed to ginkgolic acids. None Methods, limits and fundingOutcomes: Allergic contact dermatitis Limitations: Abstract only; does not say which part of the tree or seed. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Boateng 2022 A critical review of current technologies used to reduce ginkgotoxin, ginkgotoxin-5'-glucoside, ginkgolic acid, allergic glycoprotein, and cyanide in Ginkgo biloba L. seed. Food Chem · PMID 35176549 · DOI |
Narrative review |
Ginkgo seed (laboratory and processing literature) | Fresh seed holds ginkgotoxin and its glucoside (poisoning, convulsions), ginkgolic acid (cell damage and allergy), an allergic glycoprotein and amygdalin-derived hydrocyanic acid. The review compares ways to lower them. The abstract gives no figures. None Methods, limits and fundingOutcomes: Which toxins fresh seed holds Limitations: Narrative review read as abstract only; no numbers. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Han 2016 Allergic Reaction to Ginkgo Nut on FDG PET/CT. Clin Nucl Med · PMID 27276210 · DOI |
Case report |
1 woman aged 36 years | After contact with ginkgo nut she had generalised swelling and severe joint pain. The case is mainly about a scan that looked like lymphoma but was a reactive allergic change. One patient Methods, limits and fundingOutcomes: Allergic reaction Limitations: One case; the abstract does not say how she came into contact with the nut. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Hasegawa 2006 Ginkgo nut intoxication in a 2-year-old male. Pediatr Neurol · PMID 16996402 · DOI |
Case report |
1 boy aged 2 years | Vomiting and a fever-free convulsion 4 hours after eating. Toxin raised in blood and urine. Diazepam and pyridoxal phosphate given into a vein; symptoms resolved. One patient Methods, limits and fundingOutcomes: Symptoms and treatment Limitations: One case; roasted nuts. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Ji 2016 Airborne contact dermatitis caused by the sarcotesta of Ginkgo biloba. Contact Dermatitis · PMID 27870101 · DOI |
Case report |
Patient(s) with airborne skin reaction | Only the title was available: the report describes airborne contact dermatitis caused by the sarcotesta of Ginkgo biloba. No abstract exists in PubMed, so no details are given. None Methods, limits and fundingOutcomes: Skin reaction Limitations: Title only; no abstract, so numbers and details were not read. Funding and conflicts: Not stated in the abstract. Read: title-only | |
| Kajiyama 2002 Ginkgo seed poisoning. Pediatrics · PMID 11826216 · DOI |
Case report |
1 girl aged 2 years | Vomiting and diarrhoea 7 hours after eating, then a fever-free convulsion at 9 hours. Blood toxin level 360 ng/mL. Prompt pyridoxal phosphate (2 mg/kg) may have prevented more seizures. The authors say reported cases usually involve children with repeated seizures that can be fatal. One patient Methods, limits and fundingOutcomes: Symptoms and blood level of the toxin Limitations: One case; amount eaten not counted. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Kobayashi 2019 [Food Poisoning by Ginkgo Seeds through Vitamin B(6) Depletion]. Yakugaku Zasshi · PMID 30606915 · DOI |
Narrative review |
Review of ginkgo seed poisoning (in Japanese) | Review says overeating of seeds causes convulsions and vomiting, the toxin lowers PLP and raises pyridoxal and pyridoxic acid, cases occur in Asia, North America and Europe, and treatment with vitamin B6 is effective. Abstract gives no figures. None Methods, limits and fundingOutcomes: Toxin content, effect on vitamin B6 forms, case reports Limitations: Abstract only; article in Japanese. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Kosaki 2020 Epileptic Seizure from Ginkgo Nut Intoxication in an Adult. Case Rep Emerg Med · PMID 32047675 · DOI |
Case report |
1 man aged 48 years | Repeated generalised seizures of about 30 seconds, vomiting, vertigo, diarrhoea and tremor. Toxin 312 ng/mL, low active vitamin B6 (2.4 ug/L), low vitamin B1. Given 400 mg oral pyridoxal phosphate; symptoms resolved with no recurrence. One patient Methods, limits and fundingOutcomes: Symptoms, blood levels, treatment Limitations: One case. Funding and conflicts: Authors declared no conflicts of interest. Read: abstract | |
| Sado 2019 Concentrations of various forms of vitamin B(6) in ginkgo seed poisoning. Brain Dev · PMID 30366747 · DOI |
Case report |
1 girl aged 2 years | Repetitive tonic-clonic convulsions. High toxin in serum and spinal fluid. The ratio of active vitamin B6 (PLP) to pyridoxal was markedly lower in both. One patient Methods, limits and fundingOutcomes: Blood and spinal fluid vitamin B6 forms and toxin Limitations: One case. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| Yuan 2026 Safety of medicinal and edible herbs from seed sources for human consumption: A systematic review. Integr Med Res · PMID 41322721 · DOI |
Systematic review |
Human reports of adverse events after 21 medicinal and edible seeds | 703 adverse events were found across eight seeds; ginkgo seed and bitter apricot kernel caused the most. 70.8% of events were in children and 68.9% were linked to excessive intake. 96 events were serious: 29 from ginkgo seed, 60 from bitter apricot kernel, with 15 deaths and 3 cases of lasting impairment across all seeds together. Registered on PROSPERO (CRD42023426497). 703 events; 15 deaths across all seeds combined Methods, limits and fundingOutcomes: Adverse event reports and their severity Limitations: The review pools reports of many kinds, including medicinal use; deaths are not split by seed in the abstract. Funding and conflicts: Not stated in the abstract. Read: abstract | |
| s-cfs-hk-204 Centre for Food Safety, Hong Kong: Ginkgo Seed Poisoning (Food Safety Focus, issue 204, July 2023) · Source |
Regulator n/a |
Methods, limits and fundingRead: full-text | ||
| s-chp-hk-2023 Centre for Health Protection, Hong Kong: Suspected case of ginkgo seed poisoning under CHP investigation (13 June 2023) · Source |
Regulator |
Methods, limits and fundingRead: full-text | ||
| s-nccih-ginkgo NCCIH: Ginkgo (Usefulness and Safety) · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-usda-fdc-170175 USDA FoodData Central: Nuts, ginkgo nuts, dried (FDC 170175) · Source |
Reference database n/a |
Methods, limits and fundingRead: summary-only | ||
| s-usda-fdc-170584 USDA FoodData Central: Nuts, ginkgo nuts, raw (FDC 170584) · Source |
Reference database n/a |
Methods, limits and fundingRead: summary-only |
What we do not know yet
- No trial or population study of eating ginkgo nuts for any health benefit was found.
- No source says how common ginkgo nut poisoning is, or how much a person can safely eat.
- True food allergy to the kernel, and any link to poison ivy or tree nut allergy, was not quantified in any source read.
- The skin-reaction report about the fleshy coat was available by title only.
- Pregnancy, breastfeeding and medicine interactions for the cooked nut were not found, and the nutrition numbers were not re-opened at USDA on the day of writing.
How new research is added
New studies are found by a saved PubMed search and placed in a review queue before the page changes.
Lab markers
What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".
Other 2
Ginkgotoxin (4'-O-methylpyridoxine) in blood
Raised in trials
The seed toxin, measured in blood in poisoning cases. It looks like vitamin B6 and gets in the way of it.
Low certaintyResults and what it means
Why it was measured
Doctors measured it in poisoning cases to confirm the cause.
Statistical vs. clinical meaning
Case reports show the toxin is present when poisoning occurs. They cannot tell how common poisoning is or what amount is safe.
Safety implication
This is a poisoning marker, not a health benefit.
| Study | Result | People | Product |
|---|---|---|---|
| 7 | 360 ng/mL in the blood of a 2-year-old girl after a large quantity of ginkgo seeds | 1 child, case report | Ginkgo seeds eaten (amount not counted) |
| 9 | 312 ng/mL in a 48-year-old man with repeated seizures after eating ginkgo nuts | 1 adult, case report | Ginkgo nuts eaten (amount not stated in the abstract) |
Active vitamin B6 (pyridoxal phosphate, PLP) in blood
Lowered in trials
The active form of vitamin B6. The brain needs it to make GABA, a calming chemical.
Low certaintyResults and what it means
Why it was measured
The toxin is thought to block B6 from reaching its active form.
Statistical vs. clinical meaning
Consistent across several case reports, but each is one patient.
Safety implication
Doctors gave pyridoxal phosphate in these cases and symptoms improved. That is hospital treatment, not something to try at home.
Safety
What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.
Main points to know 4
- Eating many ginkgo seeds can cause seizures, especially in children. Ginkgo seeds contain a toxin called ginkgotoxin (4'-O-methylpyridoxine). It looks like vitamin B6 and gets in its way. Poisoning causes vomiting, confusion and convulsions, usually starting 1 to 12 hours after eating, and has been fatal. Children are the most affected. Authoritative guidance 12 13 11
- Cooking does not remove the toxin. The toxin is heat-stable. Cooking removes some other poisons, but not ginkgotoxin. Raw and unripe seeds are reported to be more toxic. Authoritative guidance 12
- No safe amount has been set. Hong Kong food safety authorities say ginkgotoxin has not been assessed by the international food additive experts (JECFA) and there is no health-based guidance value. They report poisoning after 10 to 50 cooked seeds at one time. That is what was reported, not a safe limit, and people vary. Authoritative guidance 12 13
- The fleshy outer coat and the tree can cause skin allergy. Touching the ginkgo tree can cause an allergic skin rash, attributed to ginkgolic acids. One report names the fleshy seed coat (sarcotesta) as the cause of an airborne rash. Wear gloves if you handle fresh fallen seeds. Case report 2 6 3
Side effects 5
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Vomiting and diarrhoea Starts 1 to 12 hours after eating (Hong Kong authorities). | Not established | moderate Resolved with treatment in the cases read | Case report 7 9 12 |
| Convulsions (tonic-clonic seizures) Cases include a 2-year-old girl, a 2-year-old boy, a 48-year-old man and a 64-year-old woman. In the 2026 review, 29 serious events were from ginkgo seed, 15 deaths occurred across all seeds combined. | Not established | serious Resolved after treatment in the cases read; deaths have been reported across the seed literature | Case report 7 5 9 1 11 |
| Dizziness, nausea, headache and fast heartbeat A 57-year-old man ate about 50 boiled seeds in soup and was admitted to intensive care. | Not established | moderate to serious Became stable after treatment | Authoritative guidance 13 |
| Allergic contact rash from the tree or the fleshy coat Ginkgolic acids are blamed for the tree rash. The sarcotesta report was read by title only. | Not established | mild to moderate Not stated in the abstracts | Case report 2 6 |
| Generalised swelling and joint pain after contact with the nut One 36-year-old woman. How she was exposed is not stated in the abstract. | Not established | moderate Not stated | Case report 4 |
Liver
No source read described liver injury from eating ginkgo nuts. LiverTox was not checked for the nut (ginkgo leaf extract is a different product).
How often. Not found.
Monitoring. No agency monitoring advice was found.
This is a safety connection. It is not evidence that Ginkgo Nuts supports liver health.
Medicines and supplements 4
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Alcohol food-drink | Not established. | In one case a 64-year-old woman ate 50 roasted seeds with 100 g of alcohol; the authors suggest alcohol may have delayed the start of poisoning. One case cannot show that alcohol makes it worse. | Case report Very low certainty 1 | Do not assume that waiting to feel ill means you are safe. |
| Vitamin B6 nutrient | Ginkgotoxin resembles vitamin B6 and blocks its change to the active form (PLP), so the vitamin in the nut itself does not protect. | In case reports, doctors gave the active form (pyridoxal phosphate) in hospital and symptoms improved. That is treatment for poisoning. Hong Kong authorities say there is no antidote and treatment is mainly relief of symptoms. | Case report Low certainty 9 1 12 | Do not self-treat with B6 supplements. Seek urgent medical care. |
| Blood thinners such as warfarin (leaf extract) prescription | Not established. | NCCIH says ginkgo may raise bleeding risk with anticoagulants. This is stated for ginkgo (the leaf extract supplement). No source read tested the cooked nut with blood thinners. | Authoritative guidance Not enough evidence 14 | If you take a blood thinner, ask a pharmacist about ginkgo in any form. |
| Medicines used for seizures prescription | Not studied. | No source read covers ginkgo nuts with seizure medicines. Because the nut can cause seizures, people with epilepsy should ask their doctor before eating it. This is a caution, not a finding from a study. | Unknown Not enough evidence | Ask a doctor. |
Who should check first 5
| Situation | Advice | Evidence |
|---|---|---|
| Young children | Most reports of serious poisoning are in small children, and Hong Kong authorities say children are especially susceptible. Ask a paediatrician before giving ginkgo nuts to a child. | Authoritative guidance 12 11 7 5 |
| Older adults and people in poor health | Hong Kong authorities name the elderly and people with poor health as groups to take particular care. | Authoritative guidance 13 12 |
| Epilepsy or a history of seizures | No source read studied this group. Because the seed toxin causes seizures, ask a doctor. | Unknown |
| Raw or unripe seeds | Reported to be more toxic. Hong Kong authorities ask the public not to eat raw seeds. | Authoritative guidance 13 12 |
| Known allergy to ginkgo or skin reaction to the tree | Avoid contact with the fleshy coat and ask an allergist. No source read links ginkgo to tree-nut or poison-ivy allergy, so that link is not claimed. | Case report 2 6 4 |
Overdose, product quality and regulators
Summary. Ginkgo seeds contain neurotoxic ginkgotoxin and its glucoside, cyanogenic glycosides and (per a review) ginkgolic acid and an allergic glycoprotein. Ginkgotoxin is the main cause of seizures.
Animal. Not reviewed.
Human doses studied. No trial gave ginkgo nuts to people. Poisoning reports involve 20 to 50 seeds in the cases read (a 2-year-old girl after 20 to 30 seeds; a 64-year-old woman after 50 roasted seeds; a 57-year-old man after about 50 boiled seeds).
High dose or long term signals. Long-term daily eating was not studied. Hong Kong authorities say as few as 10 cooked seeds at once may cause acute poisoning.
Overdose response. Seek urgent medical care. In case reports, hospital teams gave pyridoxal phosphate and sometimes diazepam. Hong Kong authorities describe treatment as mainly relief of symptoms.
Genotoxicity. Not researched.
Toxic or hazardous parts. The seed (food storage tissue holds the main toxin). The fleshy outer coat and tree carry ginkgolic acids that irritate skin.
The main concern is natural toxins, not contamination. Pre-cooked kernels in cans or packs are still ginkgo and still carry the toxin.
Natural toxins that cooking does not fully remove. Ginkgotoxin is heat-stable, so boiling or roasting reduces some toxins (such as cyanogenic glycosides) but not ginkgotoxin. 12
Processing reviews. A 2022 review compares industrial ways to lower ginkgotoxin, ginkgolic acid, the allergic glycoprotein and cyanide in the seed. The abstract gives no figures. 3
| Body | Action | Date |
|---|---|---|
| Centre for Food Safety, Hong Kong (Hong Kong) | Says ginkgo seed poisoning is real, cooking cannot completely remove the toxin, no health-based guidance value exists, and consumers should cook the seeds, limit intake, take particular care for children, the elderly and unwell people, and seek medical help if ill. source | 2023-07-01 |
| Centre for Health Protection, Hong Kong (Hong Kong) | Investigated a suspected poisoning (about 50 boiled seeds) and reminded the public not to eat large amounts or raw seeds. source | 2023-06-13 |
| NCCIH (US National Institutes of Health) (United States) | States that fresh ginkgo seeds are toxic when eaten and that serious side effects have occurred with roasted seeds. Leaf extract notes (bleeding risk with anticoagulants, may be unsafe in pregnancy) are about the supplement. source | 2025-02-01 |
When to get medical help
- Convulsions or fits, loss of consciousness, confusion, or repeated vomiting after eating ginkgo nuts: call emergency services or go to hospital. Symptoms can start up to 12 hours later, so do not wait for them to appear.
- Swelling of the face, lips or throat, or trouble breathing after contact with or eating ginkgo: call emergency services.
Stop using the product and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.
General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.
Frequently asked questions
Are ginkgo nuts safe to eat?
What does ginkgo seed poisoning feel like?
Why are children most at risk?
Does cooking make ginkgo nuts safe?
Not fully. The main toxin is heat-stable. Cooking removes some other poisons but cannot completely remove it, per Hong Kong food authorities.
Is there a safe number of ginkgo nuts?
What is ginkgotoxin?
Do ginkgo nuts help memory like the supplement?
No study shows that. The memory research used leaf extract, which is a different product.
Are ginkgo nuts nutritious?
Can ginkgo cause an allergic reaction?
Does alcohol make it worse?
One woman had seizures 9.5 hours after eating 50 roasted seeds with alcohol, and the authors suggest alcohol may have delayed the start. One case cannot show that alcohol makes it worse.
Is it safe in pregnancy or breastfeeding?
No source read covers the cooked nut. NCCIH says ginkgo (leaf extract) may be unsafe in pregnancy. Ask your doctor.
Explore by health goal
Editorial transparency
- Written by
- AlternativeMed editorial team. Research compiled with AI assistance, then checked against the sources listed.
- Medical review
- None. This page has not been reviewed by a physician or pharmacist.
- First published
- 2026-10-26
- Last substantive update
- 2026-10-26
- How we research
- We started from our existing ginkgo nut summary, read two Hong Kong government pages and the NIH ginkgo page, and checked case reports and reviews on PubMed. Only abstracts were read for studies. Little research exists on the nut as a food, so this page is short on purpose.
- How we rate evidence
- See "How we rate evidence" in the Evidence tab.
- Independence
- No product is promoted on this page. No affiliate links are shown.
Sources 16
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Azuma F, Nokura K, Kako T, Kobayashi D, Yoshimura T, Wada K. An Adult Case of Generalized Convulsions Caused by the Ingestion of Ginkgo biloba Seeds with Alcohol.. Intern Med. 2020. PMID 32132337. DOI 10.2169/internalmedicine.4196-19. (abstract)
- Barker CS, Elston DM. Botanical Briefs: Ginkgo (Ginkgo biloba).. Cutis. 2022. PMID 36179233. DOI 10.12788/cutis.0559. (abstract)
- Boateng ID. A critical review of current technologies used to reduce ginkgotoxin, ginkgotoxin-5'-glucoside, ginkgolic acid, allergic glycoprotein, and cyanide in Ginkgo biloba L. seed.. Food Chem. 2022. PMID 35176549. DOI 10.1016/j.foodchem.2022.132408. (abstract)
- Han EJ, Park HL, Kim SH. Allergic Reaction to Ginkgo Nut on FDG PET/CT.. Clin Nucl Med. 2016. PMID 27276210. DOI 10.1097/RLU.0000000000001276. (abstract)
- Hasegawa S, Oda Y, Ichiyama T, Hori Y, Furukawa S. Ginkgo nut intoxication in a 2-year-old male.. Pediatr Neurol. 2006. PMID 16996402. DOI 10.1016/j.pediatrneurol.2006.05.008. (abstract)
- Ji J, Ding Y, Qian G. Airborne contact dermatitis caused by the sarcotesta of Ginkgo biloba.. Contact Dermatitis. 2016. PMID 27870101. DOI 10.1111/cod.12646. (title-only)
- Kajiyama Y, Fujii K, Takeuchi H, Manabe Y. Ginkgo seed poisoning.. Pediatrics. 2002. PMID 11826216. DOI 10.1542/peds.109.2.325. (abstract)
- Kobayashi D. [Food Poisoning by Ginkgo Seeds through Vitamin B(6) Depletion].. Yakugaku Zasshi. 2019. PMID 30606915. DOI 10.1248/yakushi.18-00136. (abstract)
- Kosaki Y, Naito H, Nojima T, Nakao A. Epileptic Seizure from Ginkgo Nut Intoxication in an Adult.. Case Rep Emerg Med. 2020. PMID 32047675. DOI 10.1155/2020/5072954. (abstract)
- Sado T, Nakata S, Tsuno T, Sato M, Misawa Y, Yamauchi S, Inaba Y, Kobayashi D, Wada K. Concentrations of various forms of vitamin B(6) in ginkgo seed poisoning.. Brain Dev. 2019. PMID 30366747. DOI 10.1016/j.braindev.2018.10.007. (abstract)
- Yuan L, Shu B, Zhou J, Li W, Wang H, Zhou X. Safety of medicinal and edible herbs from seed sources for human consumption: A systematic review.. Integr Med Res. 2026. PMID 41322721. DOI 10.1016/j.imr.2025.101263. (abstract)
- . Centre for Food Safety, Hong Kong: Ginkgo Seed Poisoning (Food Safety Focus, issue 204, July 2023). . . (full-text)
- . Centre for Health Protection, Hong Kong: Suspected case of ginkgo seed poisoning under CHP investigation (13 June 2023). . . (full-text)
- . NCCIH: Ginkgo (Usefulness and Safety). . . (full-text)
- . USDA FoodData Central: Nuts, ginkgo nuts, dried (FDC 170175). . . (summary-only)
- . USDA FoodData Central: Nuts, ginkgo nuts, raw (FDC 170584). . . (summary-only)
Where to buy
Check the label first. Whatever you buy, look for these:
- Raw or roasted, and salted or unsalted
- A best-by date, since nuts and seeds turn rancid
- Tree nut and peanut allergy warnings
- A resealable bag, and cool storage once opened
Talk to a pharmacist or doctor before you start any supplement, especially if you take medicines. See the Safety tab for interactions.
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