I was taking Ginko Biloba for awhile, 30mg per day. One morning I had a class on analytical troubleshooting and grabbed the fresh bottle of Ginko I'd purchased the night before. I swallowed three of them and off I went. About an hour or so later, in class, I started feeling anxious and depressed. It got so bad I left class and went to sit in a corner. After a couple of hours it mostly wore off and I was able to function again.
After I got home I checked the bottle of Ginko. They were 30mg pills, not the 10mg I had taken them to be. I took a triple dose which amounted to an overdose for me.