Dynole 2−24 is an indole-based dynamin GTPase inhibitor ( IC 50 =0.56 μM for dynamin I). Dynole 2−24 is nontoxic and shows increased potency against dynamin I and II in vitro and in cells (IC ₅₀(CME) =1.9 μM). Dynole 2−24 also shows 4.4-fold selectivity for dynamin I. Dynole 2−24 is active in-cell inhibitor of clathrin-mediated endocytosis. CME: Clathrin mediated endocytosis