Out of the many conflicting research results, Ginkgo extract seem to have three effects on the human body: it improves blood flow (including microcirculation in small capillaries) to most tissues and organs; it protects against oxidative cell damage from free radicals; and it blocks many of the effects of PAF (platelet aggregation, blood clotting) that have been related to the development of a number of cardiovascular, renal, respiratory and CNS (Central Nervous System) disorders. Ginkgo can be used for intermittent claudication. Ginkgo is commonly added to energy drinks, but the amount is typically so low it does not produce a noticeable effect, except perhaps via a placebo effect from Ginkgo being listed on the label. Ginkgo may have some undesirable effects, especially for individuals with blood circulation disorders and those taking anti-coagulants such as aspirin and warfarin, although recent studies have found that ginkgo has little or no effect on the anticoagulant properties or pharmacodynamics of warfarin[7][8]. Ginkgo should also not be used by people who are taking monoamine oxidase inhibitors (MAOI) or by pregnant women without first consulting a doctor.

Ginkgo side effects and cautions include: possible increased risk of bleeding, gastrointestinal discomfort, nausea, vomiting, diarrhea, headaches, dizziness, and restlessness.

Ginkgo supplements are usually taken in the range of 40–2000 mg per day. If any side effects are experienced, consumption should be halted immediately.