The Ginkgo tree is a "living fossil", belonging to a family that dates back to dinosaur times--more than 200 million years! Gingko seeds have been used in Chinese medicine to help asthma. Lately, Gingko leaves have been getting good press for perhaps helping improve memory function. The leaves have several compounds that may help in this regard, as well as have an anti-oxidant effect in the body, and an anti-allergic effect on asthma.
(source: Herbs: A Color Guide to Herbs And Herbal Healing by Jennie Harding.)
My parents have a gingko tree in their front yard. My mom sent me a bunch of new leaves. I considered making a tincture from them, or an infusion (or decoction), but held back, deciding to research gingko leaf herbal preparations. I don't know anyone personally who works with gingko leaves, and my question on the HerbMentor.com forum has so far not yielded any results. My mom sent me some links to some articles she discovered on the internet:
I'm a bit puzzled why they harvest leaves in autumn and not in spring.
Usually when working with leaves, you harvest them when they are in their
young/new growth, and not when the energy of the tree or plant is being put to other uses (making flowers, seeds/fruit, going into the roots ...).
So, hmm. I did try nibbling on a leaf, and felt fine. I just want to be sure that no extra process is involved with using Gingko than just treating it in the usual way for infusions or tinctures--and that there isn't anything I need to worry about when using Gingko. The book above did indicate that it shouldn't be taken while pregnant, breastfeeding, or in infancy, or if you are epileptic or taking any kind of anticoagulant medication, or if you are older.
I suppose if the herb is listed in this book, it should be safe to use, except for as listed above. But perhaps it's time to reread this intro to this books to get a sense of the practical nature of its contents, in terms of home preparation.