Ginkgo improves blood flow to the brain and acts as an antioxidant. These effects may translate into some benefits for certain medical problems, but the results have been mixed. Some studies have found that in healthy people, ginkgo might modestly boost memory and cognitive speed. Other studies have not found a benefit. Several ginkgo studies have shown that it can help with memory problems caused by dementia or Alzheimer’s disease. It seems to help prevent the progression of dementia symptoms, especially if the dementia is thought to be the result of atherosclerotic vascular disease. It does not seem to prevent dementia or Alzheimer’s, however. There's good evidence that ginkgo might ease leg pain caused by clogged arteries. It might also help with some other circulation problems. In addition, ginkgo may relieve PMS symptoms, like breast tenderness and mood changes. Researchers have studied ginkgo for many other conditions, including ADHD, depression and other psychological conditions, multiple sclerosis, and tinnitus from a vascular origin. Some people are also using ginkgo to prevent high altitude sickness, though studies have not yet established that it’s effective for that. Many uses of ginkgo show promise, but more research needs to be done.