Injectable delivery systems that respond to biologically relevant stimuli present an attractive strategy for tailorable drug release. In this manuscript we report the creation of hydrogels that are formed in situ and degrade in response to clinically relevant endogenous and exogenous stimuli, specifically reducing microenvironments and externally applied light. These types of hydrogels can have broad applications in regenerative medicine as they can be loaded with proteins such as growth factors and cytokines, which can stimulate the growth of tissue.