This paper discusses the ability of Sustainable Development Reserves to embed (in Karl Polanyi's sense) the economy into the environment through the development of protocols for the sustainable management of natural resources. Based on two decades of work in the Mamirauá and Amanã Sustainable Development Reserves, we question whether the results are good, fair and viable by comparing two alternatives: unregulated markets and fully protected reserves. We evaluate the interest in sustainability; discuss who benefits and who pays for it; reflect on its potential to reduce inequalities; and discuss its economic and political viability.