Existing research points to the presence of philanthropists in global governance as funders of programmes and partners. Through an in-depth exploration of global health governance, we highlight that philanthropic organizations now shape governance by acting as producers of knowledge. Practicing ‘knowledge philanthropism’, they collect, produce and assemble the data, calculations and research which is used by International Organizations (IOs) to govern problems. In addition, philanthropies craft tools of interpretation, whether concepts, vocabularies, or concrete technological devices that embed these, which are being used for the treatment of the knowledge they themselves produce. While performing such activities, they reify their own role and enable their deeper entanglement in the knowledge machinery of global governance, fashioning data-centric activities as the solution to global health problems, and themselves as the necessary partners in this resource-intensive data collection effort. The epistemic power of philanthropists produces political effects, on health interventions and modes of governing, which deeply participate to the transformation of all matters into objects of investments for financial returns. We explore these processes in relation to global health governance, with a specific focus on medical hypertension, fashioned as a top global health priority and a necessary ‘investment’ by the World Health Organization (WHO) and other sites of global governance.