What are side effects of ginko?

Many, but often mild. Ginko biloba may cause many side effects such as bleeding disorder(surgical concern, especially when use with Aspirin etc..), constipations, allergic skin reactions, diarrhea, dizziness, impaired fertility, headache, nausea/vomitting, palppiations, restlessness, seizures, weakness, vertigo, and even bleeding in the brain/head... If you r using, consult/inform your doc.. Good luck.