Rather than being an exception, non-linearity between dose and response are the rule in biological systems. It might even be anticipated that at some doses a response opposite to that seen at high doses could be elicited (hormesis). Such non-linearity with dose has multiple implications for numerous aspects of biomedical research on aging and for experimental design. Moreover, the implications of such non-linearity are such that governmental regulatory activities and other areas of public health administration will be affected to a large extent once hormesis is widely recognized. The implications with regard to environmental intervention and subsequent regulatory decisions will certainly profoundly affect the political process, as well.