Ambitions and efforts to control human aging are presently flourishing within biomedicine, but under the banners of two competing professional camps. On one side is an “anti-aging” movement of entrepreneurs and clinicians, offering dietary supplements, cosmetics, hormone injections, and other goods and services to combat aging and its effects. On the other side are biogerontologists—biologists conducting anti-aging research–who have attained a hard-won but still fragile legitimacy in the scientific community over the past 25 years. Building on evidence from experiments in animal models, they hope to extend human life expectancy substantially, adding decades or more of healthy and active years. The activities of each of these camps raise a number of major social and ethical issues that have been addressed in the literature. This paper, however, focuses on their competitive efforts to legitimate, distinguish, and promote their activities, and the professional, social, and political implications of the rhetoric they use to do so.