We developed a comprehensive campaign and conducted two randomized controlled trials (RCTs) to increase the uptake of mental health support among Ukrainian refugees in Germany. We experimentally varied the message format and messenger, the inclusion of explicit prompts for peer-to-peer information sharing, and the option to receive a callback instead of initiating contact with the hotline. (Joint work with Alexandra Avdeenko, Luc Behaghel, Esther Duflo, Yagan Hazard, Alexander Moldavski, and Nicolas Rüsch.)