We study informed persuasion whereby a privately informed designer without ex ante commitment power chooses disclosure mechanisms to influence agents' actions. We characterize the subset of Bayes-correlated equilibria yielding every designer type a payoff higher than what they could get from any disclosure mechanism with credible beliefs. This set of interim optimal mechanisms is non-empty and tractable, and all its elements are perfect Bayesian equilibrium mechanisms of the informed-designer game. Interim optimal mechanisms are characterized via belief-based approaches in pure persuasion settings. We identify single-and multi-agent interactive environments in which ex ante optimal mechanisms are interim optimal.