I swear by the herb Ginkgo Biloba to get me through any immediate activity like shopping, visiting or when I need mental or physical energy for the next hour or so. Often I'll be in the line at the supermarket checkout or at the post office and my head will start spinning or my legs turning to jelly and I'll think, every time: Oh, oh, I forgot my Ginkgo tablet before I left home. The tablets I take are 2000mg. I couldn't live without them. Elaine.