Can we extend human lifespan? Do we need to regulate lifestyle choices or can we simply pop a pill to make us live longer? These are questions raised by two new studies demonstrating significant lifespan extension in mice fed the drug rapamycin in their diet and in calorically restricted rhesus monkeys. The excitement generated by these papers is a consequence of their novelty and possible applicability to humans: the mouse study on rapamycin is the first to highlight a drug that given in the diet late in life leads to increased mammalian longevity, and the Wisconsin monkey study is the first to report significant lifespan extension and delay in age-associated morbidity in nonhuman primates following adult-onset caloric restriction. These papers are discussed here in the context of current knowledge of molecular mechanisms of aging.