Free to read · nothing for sale · no ads, no sponsors · funded by donation
Open Source Apothecary At Home / The herbs
The most studied herb for memory — and the one whose large trials failed. Worth learning precisely because it is the clearest case of a promising observational signal that did not survive testing. — Ginkgo biloba
remedyGinkgo biloba is the oldest living tree species and the most heavily researched plant for cognition, which makes it the best test case in the whole pharmacopoeia. The large randomised trials did not find that it prevents dementia or cognitive decline. Observational studies once suggested a protective association; when the question was put to properly powered randomised trials, the association did not hold — the standard explanation being that people taking ginkgo differed from those who did not.
What remains. Peripheral arterial disease and intermittent claudication have some positive trial evidence, as does tinnitus in some reviews, though both are inconsistent. Vertigo and "cerebral insufficiency" are traditional indications with weak support.
Why it is worth studying rather than skipping. Ginkgo is the cleanest illustration of two things this handbook returns to: an observational association is not a trial result, and a plausible mechanism — ginkgo does affect platelet function and blood flow — does not guarantee a clinical benefit. If you learn one plant to inoculate yourself against supplement marketing, learn this one.
The safety side is not trivial. Ginkgo affects platelets and has been associated with bleeding, including spontaneous haemorrhage and bleeding in people on anticoagulants. It is a genuine preoperative concern. Raw ginkgo seed is toxic; the leaf preparation is the medicinal part.
In people with cognitive complaints, we are unsure whether ginkgo improves global clinical status at six months, and it may be associated with an increased risk of AEs at three months.PubMed 41641880 ↗
The meta-analysis demonstrates that patients with mild dementia benefit from EGb 761 in terms of cognition, activities of daily living, global assessment and quality of life.PubMed 39895346 ↗
In this network meta-analysis of studies of patients with AD and a follow-up period of at least 1 year, EGb 120 mg demonstrated cognitive benefits, while placebo posed the least harm for AD.PubMed 39312316 ↗
Ginkgo biloba preparation has reliable efficacy of cognitive function and global clinical assessment and safety in the treatment of AD.PubMed 32658034 ↗
Although 22 trials could be included in this review, the evidence provided is limited and mostly not relevant to clinicians or consumers.PubMed 26848926 ↗
EGb761 at 240 mg/day is able to stabilize or slow decline in cognition, function, behavior, and global change at 22-26 weeks in cognitive impairment and dementia, especially for patients with neuropsychiatric symptoms.PubMed 25114079 ↗
Quick reference
| | | |---|---| | Life | Deciduous tree, extremely long-lived | | Hardiness | Fully hardy here (zone 4-9) — the constraint is space, not cold | | Size | 15-30 m. Grow it as a specimen, not a crop. | | Sex | Dioecious — buy a named male cultivar | | Soil | Tolerates most soils, including poor and compacted | | Light | Full sun to part shade | | Harvest | Leaf in autumn, as it yellows | | Yield reality | A tree takes 20+ years to give a useful leaf harvest |
The honest assessment. Buy the leaf. Ginkgo is a large, slow tree, and seed-grown plants are of unknown sex — the female produces the notoriously foul-smelling fruit. Named male clones ('Autumn Gold', 'Saratoga') are what you plant, and they are ornamental trees rather than a medicine crop. Growing your own leaf is a twenty-year project for a preparation that is cheap, standardised in clinical trials, and best bought from a supplier who states the ginkgo flavonoid and terpene lactone content — because that standardisation is what the trials used and it is not something you can reproduce at home.
Plant it because it is a beautiful tree and a remarkable survivor. Buy the extract.
See growing-woody-and-container-medicinals for tree planting in this climate.
The form the trials used
If you grow your own leaf
Before any surgery or dental work