A standardized leaf extract with an unusually well-tested, unusually mixed record. Small gains in thinking, everyday capability and mood where memory loss is already diagnosed; no cognitive gain where thinking is intact, and no lower chance of developing dementia. Clearer signals in sudden hearing loss, dizziness and diabetic kidney disease. The real hazards are drug interactions. (Full Review)

Protocol

Standard dose

120–240 mg daily

Standardized leaf extract. Trials showing cognitive and neuropsychiatric benefit used 240 mg.

Single versus split dosing

120 mg twice daily

The more defensible pattern given the short terpene half-lives; both large prevention trials used twice-daily dosing.

Time of day

Morning with food

Evening dosing is avoided in practice because arousal-type effects and headache are reported more often at night.

Time to effect

Dementia symptoms

About 6 months

Small-to-moderate improvements in thinking, everyday function and clinician-rated global status; nothing is detectable before four to six weeks.

Depressive symptoms

4–8 weeks

Depression rating scores fell over four to eight weeks, added to usual care.

Anxiety symptoms

4 weeks

Clinician-rated anxiety fell over four weeks where anxiety is the presenting complaint.

Benefits

High: Slowed symptom progression in diagnosed dementia; reduced neuropsychiatric symptoms in dementia; faster hearing recovery in sudden hearing loss; reduced dizziness and vertigo severity; reduced tardive dyskinesia severity; reduced negative and total symptoms in chronic schizophrenia; reduced depressive symptoms as an add-on; reduced protein leakage in diabetic kidney disease

Medium: Reduced anxiety symptoms as a primary complaint

Low: Cognitive performance in cognitively healthy adults (conflicted); walking distance in peripheral arterial disease (conflicted); tinnitus symptom relief; prevention of acute mountain sickness (conflicted); blood lipid levels (conflicted); neurological recovery after acute ischaemic stroke

Speculative: Lower circulating inflammatory markers; extension of healthy lifespan by ginkgolide B

Contraindications

Epilepsy or any prior unprovoked seizure

Prior brain haemorrhage, or an aneurysm or arteriovenous malformation under observation

Platelet count below 100 × 10⁹/L, or an inherited clotting-factor deficiency (haemophilia, von Willebrand disease)

Within 14 days of planned surgery or a spinal or epidural procedure

Triple antithrombotic therapy (two platelet-blocking drugs plus an anticoagulant)

Pregnancy or breastfeeding

Child-Pugh Class B or C liver impairment

Documented allergic reaction to ginkgo, cashew, mango skin or poison ivy

Key Interactions

Antiplatelet drugs (aspirin, clopidogrel, ticagrelor, prasugrel)

Anticoagulants (warfarin, apixaban, rivaroxaban, acenocoumarol)

Over-the-counter analgesics (aspirin, ibuprofen, naproxen, diclofenac)

Over-the-counter proton pump inhibitors (omeprazole, esomeprazole)

P-glycoprotein-dependent drugs (digoxin, talinolol, dabigatran, atorvastatin)

Calcium channel blockers (nifedipine, amlodipine)

Anticonvulsants (valproate, carbamazepine, phenytoin)

Antidepressants (selective serotonin reuptake inhibitors, monoamine oxidase inhibitors)

Glucose-lowering drugs (insulin, sulfonylureas, metformin)

Supplements with additive antiplatelet effects (fish oil, vitamin E, garlic extract, curcumin, nattokinase, high-dose bromelain)

Supplements affecting drug metabolism (St. John's wort, high-dose quercetin, berberine)

Other interventions (surgery, dental extraction, endoscopic biopsy, therapeutic hypothermia)

Risk & Side Effects

High: Mild gastrointestinal symptoms and headache

Medium: Cancer risk (conflicted); reduced blood levels of CYP2C19-metabolized medications; increased blood levels of transporter-dependent medications

Low: Bleeding events with antiplatelet or anticoagulant co-use (conflicted); seizures linked to ginkgotoxin; allergic skin reactions from ginkgolic acids; undeclared isoflavone exposure from adulterated products

Speculative: Reproductive and developmental effects

Monitoring

Marker	Target	Why
Platelet count	175–350 × 10⁹/L	Sets the baseline against which any bleeding interaction is read
International normalised ratio	0.9–1.1 untreated; within target range if on warfarin	Flags drifting anticoagulation when ginkgo is added or removed
High-sensitivity C-reactive protein	Below 1.0 mg/L	Identifies the inflammatory subgroup where marker changes occurred
Alanine aminotransferase	10–26 U/L (men), 8–22 U/L (women)	Screens for the liver injury seen with ginkgolic acid exposure
Aspartate aminotransferase	10–26 U/L	Cross-checks liver signal and separates muscle from liver sources
Thyroid stimulating hormone	0.5–2.0 mIU/L	Follows the thyroid signal seen in rodent toxicology
Estimated glomerular filtration rate	Above 90 mL/min/1.73 m²	Monitors the kidney, a secondary ginkgolic acid target
Blood pressure	Below 120/80 mmHg	Establishes that any change is not attributable to ginkgo
Montreal Cognitive Assessment	26/30 or above	Gives an objective cognitive anchor rather than self-report

Cadence: Baseline before the first dose; clotting parameters and liver enzymes rechecked at 6 weeks and 6 months, then annually; cognitive score repeated at 24 weeks; for anyone on warfarin, an international normalised ratio check two weeks after starting and again after stopping.

Qualitative Assessment

Word-finding fluency and the frequency of losing a train of thought
Mental stamina in the last two hours of demanding cognitive work
Sleep onset latency and number of night awakenings
Headache frequency and character in the first month
Ease of bruising, gum bleeding, and time for small cuts to stop
Cold-hand and cold-foot episodes, and walking distance before calf discomfort
Tinnitus loudness and intrusiveness, if present at baseline

Ginkgo biloba for Health & Longevity

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment