Effectiveness
Possibly Effective
Anxiety
Clinical research shows that taking a specific ginkgo extract called EGb 761 (Dr. Willmar Schwabe Pharmaceuticals) for 4 weeks can reduce symptoms of anxiety in a greater percentage of adults with generalized anxiety disorder or adjustment disorder with anxious mood compared to placebo. After 4 weeks of treatment, a reduction in anxiety rating score of at least 50% was seen in 44% of patients treated with 480 mg/day, 39% of patients treated with 240 mg/day, and 22% of patients treated with placebo.
Dementia.
Although ginkgo does not seem to prevent progression or onset of dementia, most evidence shows that higher doses of a specific ginkgo extract (EGb761) modestly improves symptoms of Alzheimer, vascular, or mixed dementias. Meta-analyses of clinical research in patients with dementia show that taking ginkgo at higher doses of 240 mg daily for 22-24 weeks modestly improves cognition and activities of daily living when compared with placebo. Doses of 120 mg daily have not consistently shown benefit. When analyses pooled studies testing low-dose and high-dose of ginkgo together, the benefit was often not always present.
Individual studies lasting from 3 months to one year show that ginkgo leaf extract can improve some cognitive function symptoms and improve social functioning in patients with multiple types of dementia. Higher doses of ginkgo (240 mg) seem to be more beneficial than lower doses (120 mg). Although most clinical trials show benefit, there are some clinical trials with conflicting findings, suggesting inconsistent and unpredictable effects.
There has been some debate about whether ginkgo is more effective in dementia patients who have neuropsychiatric symptoms. Most clinical research shows that ginkgo is not more effective in patients with neuropsychiatric symptoms compared to those without. However, high-dose ginkgo 240 mg daily seems to modestly relieve most neuropsychiatric symptoms except psychosis.
Few clinical studies compare ginkgo leaf extract to conventional drugs such as the cholinesterase inhibitors. Preliminary comparative studies show that taking a specific ginkgo leaf extract called EGb 761 (Dr. Willmar Schwabe Pharmaceuticals) 160-240 mg daily for 22-24 weeks seems to be comparable to donepezil (Aricept) 5-10 mg daily for mild to moderate Alzheimer’s dementia. However, indirect comparisons suggest that ginkgo leaf extract might be less effective than the conventional drugs donepezil (Aricept), tacrine (Cognex), rivastigmine (Exelon) and other cholinesterase inhibitors. Preliminary studies show that taking gingko in combination with conventional medications for 12-24 weeks compared to medications alone does not improve cognitive scores by a clinically meaningful extent.
Ginkgo does not appear to be beneficial for preventing or slowing the progression of dementia. Epidemiologic research shows that taking ginkgo extract is not associated with a decreased risk of developing dementia in elderly patients with memory impairment. Three large-scale clinical trials also show that taking ginkgo extract 120 mg twice daily does not reduce the risk of developing all-cause dementia or Alzheimer disease in elderly patients with normal cognitive function or in those with mild cognitive impairment. In addition, taking ginkgo extract does not seem to prevent disease progression in Alzheimer’s patients.
Most of the clinical studies on the effectiveness of ginkgo leaf for dementia have used the standardized extracts EGb 761 (Dr. Willmar Schwabe Pharmaceuticals and Ipsen) and LI 1370 (Lichtwer Pharma). These two extracts are similar and prepared to contain approximately 24% to 25% flavone glycosides and 6% terpene lactones. Other products with similar ingredients include Ginkai (Lichtwer Pharma), Ginkgo 5 (Pharmline), Ginkgold and Ginkgo (Nature’s Way), and Quanterra Mental Sharpness (Warner-Lambert).
Premenstrual syndrome (PMS).
Taking ginkgo leaf extract orally 80 mg twice daily or 40 mg three times daily seems to produce significant relief in breast tenderness and other physical and psychological symptoms associated with PMS when started during the 16th day of the menstrual cycle and continued until the 5th day of the following cycle for up to two cycles. Specific ginkgo leaf extracts that have been assessed for this condition include Ginko T.D. (Tolidaru Pharmaceuticals) and EGb 761, which is an ingredient in several commercial products including Tebonin (Dr. Willmar Schwabe Pharmaceuticals), Tanakan (Ipsen), and Quanterra Mental Sharpness (Warner-Lambert).
Schizophrenia.
Taking a standardized ginkgo leaf extract EGb 761, 120-360 mg orally daily in addition to standard antipsychotic medications (such as olanzapine, clozapine, or haloperidol) for 8-16 weeks, can reduce total and negative symptoms of schizophrenia compared to treatment with antipsychotic medications alone. Treatment with ginkgo leaf extract might also reduce anticholinergic side effects such as thirst and constipation and adverse behavioral, cardiovascular and nerve symptoms associated with antipsychotic treatment. Additional clinical research is needed to determine the role of ginkgo on antipsychotic associated adverse events.
Tardive dyskinesia.
Clinical research shows that taking a specific ginkgo extract called EGb 761 (Yi Kang Ning, Yang Zi Jiang Pharmaceuticals Ltd., Jiangsu, China) 80 mg three times daily for 12 weeks can reduce the severity of tardive dyskinesia by at least 30% compared to placebo in schizophrenic patients being treated with antipsychotic medications.
Vertigo
Taking ginkgo leaf extract 160 mg/day orally seems to improve symptoms of vertigo and equilibrium disorders . There is evidence from two clinical studies that ginkgo leaf extract is significantly more effective than placebo and possibly as effective as betahistine for improving vertigo and dizziness caused by vascular vestibular disorders and vestibular disorders of unknown origin.
Possibly Ineffective
While some preliminary research shows a modest benefit of ginkgo leaf extract on memory and cognitive function in patients with age-related memory or thinking impairment, most clinical research shows that taking ginkgo leaf extract orally does not improve memory or attention in elderly individuals with normal mental function.
Clinical research also shows that taking a standardized ginkgo leaf extract (Thorne Research Inc., Sandpoint, ID) 240 mg daily for 3.5 years does not reduce the risk of developing age-related cognitive impairment in elderly patients aged 85 years and older who have normal cognitive function.
Antidepressant-induced sexual dysfunction
Although some preliminary clinical research suggests taking ginkgo leaf extract orally might help sexual dysfunction caused by antidepressant therapy, subsequent research indicates that it is probably ineffective. Chemotherapy-related cognitive impairment. Clinical research shows taking a specific ginkgo leaf extract called EGb 761 (Dr. Willmar Schwabe Pharmaceuticals) 60 mg twice daily starting prior to the second cycle of chemotherapy and continuing until one month after chemotherapy completion does not prevent chemotherapy-related cognitive dysfunction compared to placebo in chemotherapy naïve breast cancer patients.
Cognitive impairment
Epidemiologic research has found that taking ginkgo is not associated with a decreased risk of developing dementia in elderly patients with memory impairment. Three large-scale clinical trials also show that taking ginkgo extract 120 mg twice daily does not reduce the risk of developing all-cause dementia or Alzheimer’s disease in elderly patients with normal cognitive function or in those with mild cognitive impairment.
Hypertension
Clinical research shows that taking a standardized ginkgo leaf extract called EGb 761 (Dr. Willmar Schwabe Pharmaceuticals) 240 mg daily for up to 6 years does not reduce blood pressure compared to placebo in hypertensive patients aged 75 years or older.
Multiple sclerosis (MS)
Most clinical evidence shows that taking ginkgo leaf extract or ginkgolide B, a constituent of ginkgo leaf extract, does not improve cognition or disability in patients with multiple sclerosis. However, a single preliminary clinical study suggests that taking a standardized ginkgo leaf extract called EGb 761 (Dr. Willmar Schwabe Pharmaceuticals) may improve processing speed compared with placebo in patients with multiple sclerosis.
Seasonal affective disorder (SAD)
Taking ginkgo leaf extract orally does not seem to prevent winter depression symptoms in patients with SAD.
Tinnitus
Taking ginkgo leaf extract orally does not seem to improve symptoms of tinnitus. Although some studies have shown benefit, the majority of evidence indicates that ginkgo leaf extract is not consistently effective for patients with tinnitus.
Likely Ineffective
Cardiovascular disease (CVD)
A large-scale randomized trial shows that taking a specific ginkgo leaf extract called EGb 761 (Dr. Willmar Schwabe Pharmaceuticals) 240 mg/day orally does not significantly reduce the risk of myocardial infarction, angina, stroke, cardiovascular disease-related hospitalization, or mortality in elderly patients.
Insufficient Reliable Evidence To Rate
Preliminary clinical research suggests that taking ginkgo leaf extract 60-240 mg orally twice daily for up to 6 months might improve symptoms of AMD. There is limited evidence that ginkgo leaf extract might significantly improve distance vision in patients with AMD.
Allergic rhinitis (hay fever)
Preliminary evidence shows that applying specific eye drops (Trium, SOOFT) containing ginkgo extract 0.05% and hyaluronic acid 0.15%, three times daily for one month can decrease redness by 80%, discharge by 40%, and swelling by 10% compared to using eye drops with hyaluronic acid only in patients with seasonal allergic conjunctivitis.
Altitude sickness
The effects of ginkgo extract on altitude sickness are conflicting. Some research suggests that taking ginkgo extract 80-120 mg twice daily for 4 days before the ascent to an altitude of 4300-5400 meters significantly reduces the occurrence of symptoms of acute altitude sickness, including headache, fatigue, dyspnea, nausea, and vomiting, compared to placebo. However, a large-scale trial using a different ginkgo extract (GK501, Pharmaton Natural Health Products) 120 mg twice daily for 1-2 days before the climb from an altitude of 4280 meters to 4928 meters, shows that ginkgo extract has no effect on preventing altitude sickness. Also, another small study suggests that taking ginkgo extract 120 mg twice daily for 3 days before an ascent does not reduce altitude sickness compared to placebo. The conflicting results may be due to differences in starting baseline altitudes before ascent, duration of pretreatment period, or the source of the ginkgo product.
Asthma
Clinical research shows that a taking two capsules of a specific combination product (AKL1, AKL International Ltd.) containing ginkgo extract 130 mg/capsule, ginger 100 mg/capsule, and Picrorhiza 270 mg/capsule twice daily for 12 weeks does not improve lung function, respiratory symptoms, or quality of life compared to placebo in adult patients with asthma.
Attention deficit-hyperactivity disorder (ADHD)
The effects of ginkgo on ADHD symptoms are inconsistent and unclear. One clinical study shows that taking a standardized ginkgo extract (Ginko T.D., Tolidaru Pharmaceuticals) 80-120 mg daily for 6 weeks is less effective than methylphenidate 20-30 mg/day in children aged 6-14 years with newly-diagnosed ADHD. An improvement in a teacher/parent ADHD rating scale of at least 40% was seen in only 8% of children taking this ginkgo extract compared with 64% in children taking methylphenidate. Another clinical study in children aged 6-12 years with ADHD shows that taking the same standardized gingko extract 80-120 mg daily in combination with methylphenidate 20-40 mg daily for 6 weeks does not improve parent- or teacher-rated ADHD scores by a clinically meaningful amount compared to methylphenidate alone. However, there is preliminary evidence that taking a specific combination product (AD-fX, CV Technologies) containing ginkgo leaf extract, in combination with American ginseng, might significantly improve ADHD symptoms such as anxiety, hyperactivity, and impulsivity in children aged 3-17 years.
Autism spectrum disorder
Clinical research shows that taking a specific ginkgo extract (Ginko T.D., Tolidaru Pharmaceuticals) 80-120 mg/day for 10 weeks along with risperidone 1-3 mg/day does not improve symptoms of autism compared to risperidone alone in autistic children aged 4-12 years.
Chronic obstructive pulmonary disease (COPD)
Clinical research shows that taking two capsules of a specific combination product (AKL1, AKL International Ltd.) containing ginkgo extract, ginger, and Picrorhiza twice daily for 8 weeks does not improve respiratory symptoms compared to placebo in patients with COPD.
Cocaine dependence
Clinical research suggests that taking a standardized ginkgo leaf extract called EGb 761 120 mg twice daily for 10 weeks does not help maintain abstinence from cocaine use compared to placebo in cocaine-dependent patients.
Cognitive function
Clinical research shows that taking ginkgo leaf extract 120-240 mg daily for up to 12 weeks might improve some measures of cognitive function such as working and long term memory, attention based tasks, speed of information processing, executive function, immediate and delayed recall, and recognition in healthy adults. However, other clinical studies and one clinical review show no significant effect of ginkgo on gait ability, attention, memory, or executive function regardless of participant age, dose, or formulation used. Due to the small number of study participants, significant differences in baseline cognitive function between groups, and variability in outcome measures, no definitive conclusions can be drawn. Larger scale studies are needed to determine the effect of gingko on cognitive function in healthy individuals.
There is also conflicting evidence about the effect of gingko on cognitive function when taken in combination with other products. Some research suggests that taking ginkgo in combination with Panax ginseng or codonopsis enhances memory in healthy young or middle-aged adults, and the combinations might be more effective than the individual products . However, other clinical research shows that taking gingko combined with Panax ginseng (Gincosan, Pharmaton Natural Health Products) or bacopa extract (Ginkgo Brahmi, Blackmore’s Ltd.) for up to 12 weeks does not improve cognition compared to placebo in healthy adults.
Colorectal cancer
Preliminary clinical research suggests that intravenous ginkgo extract (EGb 761 ONC), in combination with 5-fluorouracil, might be useful for metastatic colorectal cancer.
Depression
Preliminary clinical research in elderly patients shows that taking an unknown dose of a specific ginkgo extract (Harbin HaoBo Pharmaceutical Co., Ltd.) in conjunction with citalopram 20 mg daily for 12 weeks improves depression scores by 75% or more in an additional 3% of patients when compared with taking citalopram alone. Taking ginkgo extract with citalopram also produces a faster onset of action when compared to taking citalopram alone. However, it is not clear if these improvements are clinically significant.
Diabetic retinopathy
There is some preliminary evidence that taking a specific ginkgo leaf extract called EGb 761 120 mg/day orally for 6 months can significantly improve measures of color vision in patients with early diabetic retinopathy.
Dyslexia
Preliminary clinical research suggests that taking a standardized ginkgo leaf extract called EGb 761 80 mg daily for an average of 34 days can help reduce dyslexia compared to baseline in children aged 5-16 years.
Fibromyalgia
Preliminary clinical research suggests that taking tablets containing ginkgo extract (Bio-Biloba, Pharma Nord) 200 mg/day in conjunction with capsules containing coenzyme Q10 (Bio Quinone Q10, Pharma Nord) 200 mg/day orally for 84 days improves patient’s quality of life, such as physical fitness levels, emotional feelings, social activities, overall health, and pain, compared to baseline.
Gastric cancer
Preliminary evidence suggests that taking carbohydrates from the outer layer of ginkgo fruit 250 mg orally twice daily for 30 days may reduce tumor size in patients with gastric cancer compared to pretreatment.
Glaucoma
A small observational study has found that ginkgo leaf extract 80 mg twice daily is associated with reduced progression of visual field damage in patients with normal tension glaucoma. Furthermore, a small clinical study in patients with normal tension glaucoma shows that taking ginkgo leaf extract 40 mg three times daily for up 4 weeks might improve pre-existing damage and reduce the progression of damage to the visual field. However, conflicting evidence exists. Another small study in patients with newly diagnosed normal tension glaucoma shows that taking a specific ginkgo extract (Ginaton, Dr. Willmar Schwabe Pharmaceuticals) 40 mg three times daily for 4 weeks does not improve damage or progression of glaucoma. Reasons for the discrepancies may be due to the formulation of ginkgo leaf extract used or the severity of glaucoma at baseline.
Hearing loss
There is preliminary evidence that ginkgo leaf extract 120 mg orally twice daily might help short-term idiopathic hearing loss. However, because many of these patients recover spontaneously, evaluating its effectiveness for this use is difficult.
Hemorrhoids
Preliminary clinical evidence suggests that taking a combination of ginkgo extract, troxerutin, and heptaminol for one week may decrease some symptoms of hemorrhoids, including bleeding, pain, feelings of incomplete defecation, and discharge.
Migraine headache
Preliminary clinical evidence shows that ginkgolide B, a constituent of ginkgo biloba extract, may help prevent migraines in children. Also, a specific product (Migrasoll, Pharmaval Srl) containing ginkgolide B 60 mg, coenzyme Q10 11 mg, and vitamin B2 8.7 mg, taken twice daily for 4 months, may help prevent migraines in women.
Ovarian cancer
Epidemiological evidence found that use of ginkgo extract for 6 months is associated with a decreased risk for developing ovarian cancer.
Pancreatic cancer
Preliminary clinical research suggests that a specific intravenous ginkgo extract called EGb 761 ONC, given with 5-fluorouracil, might slow the progression of pancreatic cancer in some patients. However, since the study did not include a control group, it is unclear if the effects of treatment were greater than the effects of 5-fluorouracil alone.
Peripheral arterial disease (PAD)
Some evidence shows that taking a specific ginkgo leaf extract called EGb 761 (Dr. Willmar Schwabe Pharmaceuticals and Ipsen) orally increases pain-free walking distance in patients with Fontaine’s IIb peripheral arterial occlusive disease and intermittent claudication and might decrease overall peripheral vascular disease (PVD) event incidence such as surgery or amputation in elderly patients. Significant benefit has been found with doses as low as 120-160 mg per day. However, there is some evidence that a higher dose of 240 mg per day might be more beneficial in some patients.
Although some research is positive, other research shows that taking a specific ginkgo leaf extract called EGb 761 (Dr. Willmar Schwabe Pharmaceuticals) 300 mg daily for 16 weeks does not significantly improve maximum treadmill walking time compared to placebo in patients with PAD. A reason for this discrepancy may be due to the duration of treatment. An analysis of clinical evidence shows that taking ginkgo leaf extract does not significantly improve maximum treadmill walking distance compared to placebo in patients with Fontaine stage II PVD and intermittent claudication when administered for 6-8 weeks or 12-16 weeks, but does increase maximum treadmill walking distance by about 85 meters when administered for at least 24 weeks.
Quality of life
Preliminary clinical evidence suggests that taking a standardized ginkgo leaf extract called LI 1370 (Lichtwer Pharma) 120 mg daily for up to 6 months may improve quality of life measures such as activities of daily living, mood, sleep, and alertness in elderly individuals.
Radiation exposure
Preliminary clinical research suggests that taking a standardized gingko leaf extract called EGb 761 (Tanakan, Ipsen) 120 mg daily for 2 months might reduce clastogenic factors in the blood of patients who had previously been irradiated. The reduction in clastogenic factors was observed for at least 7 months after initiation of ginkgo in most patients.
Radiation dermatitis
Preliminary clinical research suggests that topically applying a specific cream product (Radioskin 2, Herbalab di Perazza Massimiliano Company), which contains ginkgo extract, Aloe vera, and metal esculetina, along with another specific cream product (Radioskin 1, Herbalab di Perazza Massimiliano Company), which contains alga atlantica and ethylbisiminomethylguaicolo manganese cloruro, may improve skin hydration and reduce skin toxicity associated with radiation therapy in patients with breast cancer. The creams were applied topically two to three times daily at least 3 hours before and after radiation treatment from 15 days prior to radiation until one month after completion.
Raynaud syndrome
Some research suggests that taking a standardized ginkgo extract (Seredrin, Health Perception Ltd.) 120 mg orally three times daily for 10 weeks can decrease the number of painful attacks per week in patients with Raynaud syndrome. However, other research suggests that ginkgo extract is no different than placebo in decreasing the number of attacks in these patients. Also, another study shows that taking ginkgo extract 120 mg daily is less effective than nifedipine SR 30 mg/day orally in decreasing Raynaud syndrome flares.
Sexual dysfunction
Some clinical research shows that taking a ginkgo leaf extract 300 mg daily for 8 weeks does not significantly improve sexual function in women with sexual arousal disorder. However, other preliminary clinical research shows that taking a specific combination product (ArginMax for Women, Daily Wellness Company) containing ginkgo leaf extract, Panax ginseng root extract, damiana leaf extract, L-arginine, multivitamins, and minerals for 4 weeks can improve sexual satisfaction compared to placebo in women who are self-reported to have sexual dysfunction.
Stroke
There is contradictory evidence about the effectiveness of ginkgo extract for improving recovery in patients with acute ischemic stroke. Some evidence from poor quality research suggests that more patients have neurological improvement when treated with ginkgo. However, a higher quality trial found no neurological improvement in patients treated with ginkgo compared to placebo.
Vitiligo.
Preliminary clinical research suggests that taking a specific ginkgo extract (Ginkgo Plus, Seroyal) 120 mg daily reduces the progression of vitiligo vulgaris and size of the lesions compared to baseline.
