This case study appears in: Mays C, Laborie L, Griset P (eds) (2022) Inventing a shared science diplomacy for Europe: Interdisciplinary case studies to think with history. With the end of colonial empires in the 1960s, European countries had to develop political, diplomatic, and economic strategies to gain access to natural resources. Pharmaceuticals are made mainly from natural substances. Tension exists between the richest countries expressing a huge demand for medicines, and the poorer intertropical countries, in which are found the required natural products and medicinal plants. Natural substances chemists need access to raw materials found in tropical regions in order to research and uncover new chemical compounds. How did scientists behave when French science policy on such international activity was not explicit, and when funding was lacking? Or when French diplomacy was unaware of the academic and industrial importance of natural products? This case examines how French scientists had to be pragmatic and create new processes of cooperation, collaboration, and funding in order to continue to explore new territories, study new species, and discover new molecules. It considers how they reconciled these means to produce new knowledge with addressing the growing endangerment of their subject species, as continuous overexploitation of the intertropical zone has critically impacted environmental biodiversity.