Meta, Twitter, YouTube, and other social media websites have struggled to make effective governance decisions on behalf of billions of users every day, and misinformation continues to run rampant. At an individual level, many users of these systems find themselves trapped in health misinformation bubbles, sometimes built inadvertently via the networks they have created. In an attempt to address these challenges, this team of researchers will design, build, and evaluate network-transforming interventions: software-assisted systems to alter underlying networks that spread health misinformation online. In this context, a health misinformation monitor Twitter account will continuously track emerging health misinformation on English-speaking Twitter and deliver counter-messaging to the recipients of that misinformation—with the aim of motivating users to unfollow the source. The research team will introduce a roadmap for misinformation interventions that can operate outside of corporations and governments, fill the gaps left by the constraints of industry and regulation, and promote safe and trustworthy online experiences.