How to identify win–win interventions that benefit human health and conservation

To reach the Sustainable Development Goals, we may need to act on synergies between some targets while mediating trade-offs between other targets. But what, exactly, are synergies and trade-offs, and how are they related to other outcomes, such as ‘win–win’ solutions? Finding limited guidance in the existing literature, we developed an operational method for distinguishing win–wins from eight other possible dual outcomes (lose–lose, lose–neutral and so on). Using examples related to human health and conservation, we illustrate how interdisciplinary problem-solvers can use this framework to assess relationships among targets and compare multi-target interventions that affect people and nature. Reaching the Sustainable Development Goals requires recognizing trade-offs and synergies among targets. Focusing on conservation and human health, this Perspective suggests how to productively distinguish win–wins from other outcomes.