Some of Ginkgo Biloba side effects:
Mild stomach or intestinal complaints, headache, and allergic skin reactions have been reported.
Ginkgo biloba appears to be useful in memory loss due to aging or Alzheimer's disease, but is probably of little benefit in the young who have normal brain function and memory. Middle aged and older individuals may find ginkgo to be helpful in sharpening the mind.
Took the stuff once too and remember being agitated, however could never remember to take it again(wish I was kidding).....until it expired.