Dehydroepiandrosterone (DHEA) has been known since the 1930s. Only in the last 10 years has it attracted much attention outside those studying the feto-placental unit (in which it has long been known to play a role: Diczfalusy (1984)) or as a clinical aid in the diagnosis of some ovarian disorders. Recently, however, increasingly large numbers of (mostly middle-aged) people have been taking DHEA (usually in an unregulated manner), and it has acquired a popular reputation as a rejuvenating or anti-ageing therapy. Such compounds have a long history: the elixir of youth has been a recurring feature of many a nostrum, and the foundation of many doubtful reputations over the centuries. Is DHEA just another passing fad, destined to join the monkey glands and rhino horns of yesteryear? Or is there some empirical basis for the current interest in this steroid? Here we focus on the current evidence that DHEA has a role to play in the detrimental effects of age on the brain.