Home Ingredients Ginkgo 24/6 (Standardized Ginkgo biloba Extract)
Cognitive

Ginkgo 24/6 (Standardized Ginkgo biloba Extract)

Ginkgo biloba
Evidence Level
Moderate
2 Clinical Trials
2 Documented Benefits
3/5 Evidence Score

Ginkgo 24/6 is a Ginkgo biloba leaf extract standardized to about 24% flavone glycosides and 6% terpene lactones, the same specification as EGb 761, the extract used in the large trials cited on this page. In a meta-analysis of 9 trials in 2,561 people diagnosed with cognitive impairment or dementia, 240 mg a day for 22 to 26 weeks was linked to smaller declines in thinking and daily-living scores than placebo. In a separate trial of 3,069 adults aged 72 to 96 with normal cognition or mild cognitive impairment, 120 mg twice daily for a median of about six years did not slow cognitive decline compared with placebo. Headache, dizziness and digestive upset are the most commonly listed side effects. Ginkgo may increase bleeding tendency, so ask a doctor before combining it with blood thinners, and stop it a few days before surgery.

Studied Dose 240 mg a day of EGb 761 for 22 to 26 weeks in the pooled trials in people with cognitive impairment or dementia, where benefits were mainly linked to that dose. The large trial in older adults used 120 mg twice daily for a median of 6.1 years.
Active Compound Ginkgo biloba leaf extract standardized to about 24% flavone glycosides and 6% terpene lactones (ginkgolides and bilobalide).

Benefits

Cognition and memory

A meta-analysis of 9 randomized trials in 2,561 people diagnosed with cognitive impairment or dementia found that 240 mg a day of this extract type for 22 to 26 weeks was linked to smaller declines in cognition and daily-living scores than placebo. It has not been shown to sharpen memory in healthy adults, and a six-year trial in 3,069 older adults found no significant slowing of decline.

Supported by Trial 1, Trial 2

Memory and attention in older adults

In a randomized trial of 3,069 community-dwelling adults aged 72 to 96 with normal cognition or mild cognitive impairment, 120 mg twice daily for a median of 6.1 years did not change the yearly rate of decline in memory, attention, language, visual-spatial or executive skills compared with placebo.

Supported by Trial 2

Mechanism of action

1

Blood viscosity and clotting measures

A meta-analysis of 18 randomized trials in 1,985 adults found standardized ginkgo extract lowered blood viscosity but did not significantly change platelet aggregation, fibrinogen, or two standard clotting times. The EU herbal monograph, by contrast, lists reduced platelet aggregation among the effects seen in human studies.

2

Absorption of terpene lactones

The EU herbal monograph reports that after a 120 mg oral dose of the extract as a solution, about 80% of ginkgolide A, 88% of ginkgolide B and 79% of bilobalide reached the bloodstream.

Clinical trials

1
EGb 761 and Cognition in Cognitive Impairment and Dementia: Meta-Analysis
PubMed

Systematic review and meta-analysis of 9 randomized placebo-controlled trials of the standardized extract EGb 761, lasting 22 to 26 weeks. (Tan et al. 2015, J Alzheimers Dis)

2,561 patients diagnosed with cognitive impairment or dementia.

Pooled results favoured EGb 761 over placebo for cognition (weighted mean difference -2.86), activities of daily living (standardized mean difference -0.36) and clinicians' global impression of change (Peto odds ratio 1.88). These benefits were mainly linked to 240 mg a day. The authors concluded the extract can stabilize or slow decline rather than reverse it, and safety data showed no important concerns.

2
Ginkgo and Cognitive Decline in Older Adults: GEM Trial
PubMed

Randomized, double-blind, placebo-controlled trial of EGb 761, 120 mg twice daily, with a median follow-up of 6.1 years at 6 US academic centers. (Snitz et al. 2009, JAMA)

3,069 community-dwelling adults aged 72 to 96 with normal cognition or mild cognitive impairment.

Yearly rates of decline did not differ between ginkgo and placebo in memory, attention, visual-spatial skills, language or executive function, or on two global cognitive scales. Results did not differ by age, sex, education, APOE4 status or baseline mild cognitive impairment.

Side effects and drug interactions

Common Potential side effects

Headache is the most commonly listed side effect; dizziness, diarrhea, abdominal pain, nausea and vomiting are also common, according to the EU herbal monograph.
Bleeding of the eye, nose, brain or gut has been reported in ginkgo users, and the EU herbal monograph says ginkgo might make bleeding more likely. A meta-analysis of 18 trials found no significant change in platelet aggregation or standard clotting times.
Allergic skin reactions such as redness, swelling, itching and rash can occur, and severe allergic reactions have been reported.
In people with epilepsy, further seizures linked to ginkgo cannot be excluded.
The EU monograph advises against use in pregnancy.

Important Drug interactions

Blood thinners and antiplatelet medicines, including warfarin, clopidogrel, aspirin and other NSAIDs: ginkgo may change their effect. Use it only with your doctor's advice.
Efavirenz: ginkgo may lower efavirenz levels, and the EU monograph advises against combining them.
Dabigatran and nifedipine: the EU monograph reports that ginkgo may raise blood levels of these medicines, so use caution and ask your doctor before combining.
Epilepsy and seizure medicines: talk to your doctor first, because further seizures cannot be excluded.
Surgery: the EU monograph advises stopping ginkgo 3 to 4 days before surgery. Tell your surgeon or dentist you have been taking it.

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Frequently asked questions about Ginkgo 24/6 (Standardized Ginkgo biloba Extract)

What is Ginkgo 24/6?

Ginkgo 24/6 is a Ginkgo biloba leaf extract standardized to about 24% flavone glycosides and 6% terpene lactones, the same specification as EGb 761, the extract used in the large trials cited on this page.

What is Ginkgo 24/6 used for?

Ginkgo 24/6 is researched primarily for Cognitive. A meta-analysis of 9 randomized trials in 2,561 people diagnosed with cognitive impairment or dementia found that 240 mg a day of this extract type for 22 to 26 weeks was linked to smaller declines in cognition and daily-living scores than…

What is the recommended dosage of Ginkgo 24/6?

The clinically studied dose is 240 mg a day of EGb 761 for 22 to 26 weeks in the pooled trials in people with cognitive impairment or dementia, where benefits were mainly linked to that dose. The large trial in older adults used 120 mg twice daily for a median of 6.1 years. Always follow the product label and check with a healthcare provider for personal advice.

Is Ginkgo 24/6 safe, and does it have side effects?

Side effects and cautions reported for Ginkgo 24/6 include: Headache is the most commonly listed side effect; dizziness, diarrhea, abdominal pain, nausea and vomiting are also common, according to the EU herbal monograph. It may also interact with some medications. Ginkgo 24/6 is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Ginkgo 24/6 interact with any medications?

Possible interactions include: Blood thinners and antiplatelet medicines, including warfarin, clopidogrel, aspirin and other NSAIDs: ginkgo may change their effect. Use it only with your doctor's advice. Efavirenz: ginkgo may lower efavirenz levels, and the EU monograph advises against combining them. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Ginkgo 24/6?

NutraSmarts rates the evidence for Ginkgo 24/6 as Moderate (3 out of 5). It is backed by 2 study summaries and 4 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(4 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Tan MS, Yu JT, Tan CC, Wang HF, Meng XF, Wang C, Jiang T, Zhu XC, Tan L. Efficacy and adverse effects of ginkgo biloba for cognitive impairment and dementia: a systematic review and meta-analysis. J Alzheimers Dis. 2015;43(2):589-603. doi: 10.3233/JAD-140837.PubMedUsed to support: Meta-analysis of 9 randomized trials (22 to 26 weeks, 2,561 patients with cognitive impairment or dementia). EGb 761 beat placebo on cognition, daily activities and clinicians' global impression, mainly at 240 mg a day, and safety data showed no important concerns. It does not address healthy adults.
  2. Snitz BE, O'Meara ES, Carlson MC, Arnold AM, Ives DG, Rapp SR, Saxton J, Lopez OL, Dunn LO, Sink KM, DeKosky ST, Ginkgo Evaluation of Memory (GEM) Study Investigators. Ginkgo biloba for preventing cognitive decline in older adults: a randomized trial. JAMA. 2009;302(24):2663-70. doi: 10.1001/jama.2009.1913.PubMedUsed to support: GEM trial: 3,069 adults aged 72 to 96 took 120 mg EGb 761 twice daily or placebo for a median of 6.1 years. Rates of decline in memory, attention, visual-spatial skills, language, executive function, the 3MSE and the ADAS-Cog did not differ from placebo. The full text describes EGb 761 as standardized to about 24% flavone glycosides and 6% terpene lactones.
  3. Kellermann AJ, Kloft C. Is there a risk of bleeding associated with standardized Ginkgo biloba extract therapy? A systematic review and meta-analysis. Pharmacotherapy. 2011;31(5):490-502. doi: 10.1592/phco.31.5.490.PubMedUsed to support: Meta-analysis of 18 randomized trials in 1,985 adults: standardized ginkgo extract lowered blood viscosity but did not significantly change ADP-induced platelet aggregation, fibrinogen, aPTT or prothrombin time; a small aPTT drop at 240 mg a day or more was judged not clinically relevant.
  4. Committee on Herbal Medicinal Products (HMPC), European Medicines Agency European Union herbal monograph on Ginkgo biloba L., folium (EMA/HMPC/321097/2012) European Medicines Agency. 2015;Final monograph, EMA/HMPC/321097/2012..SourceUsed to support: Not PubMed-indexed; EU regulatory monograph. Lists headache as very common and dizziness, diarrhea, abdominal pain, nausea and vomiting as common side effects, with reports of bleeding and allergic skin reactions. Advises stopping ginkgo 3 to 4 days before surgery, says further seizures in people with epilepsy cannot be excluded, and advises use only after consulting a doctor alongside anticoagulant or antiplatelet treatment. Does not recommend use with efavirenz, advises caution with dabigatran, reports raised nifedipine levels, notes reduced platelet aggregation in human pharmacology data, and contraindicates use in pregnancy.