Ginkgo biloba: the standardized dose, the evidence, and cost

Studied doses of ginkgo biloba are about 120-240 mg per day of a standardized leaf extract, usually split into two or three doses. The label detail that matters is the "24/6" standardization (24% flavone glycosides and 6% terpene lactones), the ratio used in the well-studied EGb 761 extract. The honest picture on memory is that the evidence is weak and mixed in healthy people, so buy on cost per standardized dose rather than on marketing claims.

What ginkgo is used for

Ginkgo biloba is an extract of the leaves of the ginkgo tree, marketed mostly for memory and circulation. Its active compounds fall into two groups: flavone glycosides (antioxidant flavonoids) and terpene lactones (ginkgolides and bilobalide). The idea behind it is improved blood flow and antioxidant activity, which is why it shows up in "brain" and "focus" formulas.

It is one of the most-studied botanicals, but "most-studied" is not the same as "proven to work." The results depend heavily on who was tested and what was measured.

The standardized dose

A practical target is 120-240 mg per day of a standardized extract, taken as split doses rather than all at once.

• Start at the low end (around 120 mg) and give it several weeks, since effects, if any, build slowly.
• Split the dose into two or three servings across the day.
• Ginkgo is usually taken consistently rather than as an as-needed pill.

The dose only means something if the extract is standardized, which is where the label comes in.

What "24/6" means

The "24/6" you see on quality ginkgo products is a standardization spec:

• 24% flavone glycosides
• 6% terpene lactones

This is the ratio used in EGb 761, the extract behind most of the serious research. A capsule that just says "ginkgo leaf 500 mg" with no standardization tells you the weight of powder but nothing about active content, so two products at the same milligram count can differ a lot in what they actually deliver. When you compare cost, compare standardized 24/6 extracts with each other.

Does ginkgo improve memory?

Here is the honest version. In healthy people looking for a memory boost, the evidence is weak and inconsistent, and you should not count on a noticeable effect. Ginkgo has been studied more in older adults and specific clinical contexts, but it is not a proven treatment for dementia and should not be used as one. If memory or cognition is a real concern, that is a conversation for a doctor, not a supplement label. Not medical advice.

Safety: the blood-thinning caveat

The most important safety point is that ginkgo may have a mild blood-thinning effect. Standardised leaf extract itself is, per NCCIH, generally well tolerated, with dizziness, gastrointestinal symptoms and headache as the common complaints — the seeds are the dangerous part of the plant, and fresh ginkgo seeds are toxic taken orally, with serious effects also reported from roasted seeds and raw plant material. Nothing sold as a leaf-extract capsule contains them, but "whole ginkgo" preparations are worth avoiding.

• Avoid it with anticoagulant or antiplatelet medication (for example warfarin or aspirin) unless a clinician says otherwise.
• Stop it before scheduled surgery and tell your care team you have been taking it.
• Be cautious if you have a bleeding disorder.

Mild digestive upset and headaches are the other commonly reported effects. Discuss ginkgo with a pharmacist if you take any regular medication. Not medical advice.

How to buy ginkgo by cost per dose

Because active content varies so much, cost per dose is the only fair comparison:

• Confirm the extract is standardized to 24/6. If it is not, you cannot really compare it.
• Note the milligrams of standardized extract per serving and how many servings hit your 120-240 mg/day target.
• Divide the total price by the number of doses in the bottle to get a real cost per standardized dose.

A cheap bottle of unstandardized "ginkgo leaf" often looks like a bargain but delivers unknown active content, so it can cost more per effective dose than a standardized product.

Compare current prices per dose on /nutrients/ginkgo, see the best current value picks on /best/ginkgo, and read exactly how we calculate cost per dose on /methodology.

Buy a standardized 24/6 extract that reaches your target dose at the lowest cost per dose, and keep the blood-thinner caution in mind before you start.