EGb 761 (extract of Ginkgo biloba 761) comes from a single type of tree, a living fossil, the only remaining representative of its phylum; it contains chemical substances unknown in other living things. The flavonoid fraction accounts for 24% of the extract and terpenes (ginkgolides and bilobalide) for 6%. It acts in many different situations and organs, and exerts protective effect on neurodegenerative, sensory, and vascular diseases. In all of these different domains, it has been shown to act at all levels of the organization of life: molecules, cells, tissue, entire organisms, sometimes in particular situations (related to a particular pathology or to senescence) and in humans. Although many questions remain, what stands out in the literature is the overall consistency of the data. Particularly remarkable is that EGb 761 does not exert a specific unidirectional action (activating or inhibiting) in these various domains of physiology and pathology; rather it is regulatory, helping the organism to adapt to the circumstances in which it finds itself.