This lecture explores connections between bioprospecting for immunotherapies, pharmaceutical regulation and human-environmental relations in Latin America (particularly Brazil) and Europe. The aim is to analyze, from a transnational and relational perspective, aspects of the mobility, re-hierarchization and use of substances with potential antigenic power that were once forbidden in the context of disputes between immunosuppression and immunostimulation as competing therapeutic models to treat immunopathologies and depression. The guiding question is: How has the use of palliative immunosuppressants as a matter of course been questioned by multiple actors over decades not only at central sites of legitimate knowledge production in the Global North but also in the Global South, while substances that were previously tabooed (such as Deltorphine, Melittin, Beta-Glucana, and cannabinoids) seem now to reappear as potential therapeutic agents that can be gradually rehabilitated as biotechnological innovations?