This data package contains (meta) data, analysis scripts, and relevant documents for the project: “Does protection come at a cost? A random stimuli approach to investigating the (side-)effects of misinformation inoculations”. The project investigated whether misinformation inoculations – an intervention aimed at informing people of the threat of misinformation and the strategies used to spread it – can have unintended side-effects, such as reducing the credibility of true news, and increasing people's cynicism.