The controversy over the prescription drug, alosetron, is examined in order to investigate what is permitted to count as ‘therapeutic advance’ and ‘therapeutic breakthrough’ within pharmaceutical innovation and regulation. It is argued that those official accounting categories can mask very modest efficacy of some drugs by reference to the official techno-scientific evidence, thus leading to questionable acceptance of risks to public health. This is explained by: the drug availability options set by the commercial interests of manufacturers; the FDA management's need (...) to demonstrate rapid approval of therapeutic advances to their budgetary masters, especially in the context of patient demands for access to new drugs; and the increasing capacity of patient groups, sometimes in collaboration with pharmaceutical manufacturers, to challenge techno-scientific expertise and evidence with experiential testimony. It is concluded that regulatory policy-makers need much more sophisticated accounting systems for differentiating between drugs defined as significant therapeutic advances, and between drugs (‘therapeutic breakthroughs’ fast-tracked to treat serious or life-threatening conditions. Contrary to some STS analyses, the desirability of an ascendancy of patients’ anecdotal evidence in regulatory decisions for public health is questioned. (shrink)