Between 1817 and 1831, four German scientists – Karl von Martius, Georg Langsdorff, Ludwig Riedel, and Friedrich Sello – undertook expeditions in Brazil with the goal of collecting natural specimens, particularly focusing on Brazilian cinchona plants. Renowned for their medicinal properties, especially in the treatment of fever diseases, cinchona specimens were extensively utilized by local Brazilian communities. The widespread use of cinchona raises important questions regarding how German scientists acquired knowledge of the therapeutic properties of plants, previously unknown within German pharmacology. This paper argues that the German understanding of Brazil's cinchona trees was situated within an imperialist endeavor that not only appropriated indigenous knowledge but also involved conducting experiments on these plants and their effects on local populations. This hybridization of knowledge about cinchona was characterized by an asymmetrical dominance of German pharmacological experimentation, which sought to enhance organic life and establish utopian, “healthy” German societies, in both German territories and Brazil. Consequently, German chemical experiments with Brazilian cinchona specimens intersected with biopolitical practices, aimed at manipulating both plant and human life through therapeutic interventions.