Does Rustoleum paint actually stop rust?

Rust-Oleum paint does help stop rust when used correctly as part of proper surface preparation, though it does not magically stop rust if you just paint over heavy loose rust without prep. Rust-Oleum's flagship Stops Rust line is formulated with fish oil and other corrosion inhibitors that create barrier to moisture and oxygen, which are required for rust to form, and it contains rust-inhibitive pigments that slow corrosion on properly prepared metal. For best results, you must remove loose rust, dirt, and flaking paint with wire brush or sandpaper, clean surface, and ideally apply Rust-Oleum Rusty Metal Primer or Rust Reformer that chemically converts remaining rust into inert black coating before topcoat. If you just paint over thick loose rust, rust will continue underneath and paint will peel within months. When applied to clean bare metal or properly primed rusty metal, Rust-Oleum does effectively stop rust for several years, especially for outdoor furniture, railings, and automotive parts, with many users reporting 3 to 5 years protection before recoat needed. It is not permanent, as any chip exposing metal will allow rust to restart. For severe rust, products like POR-15 or Corroseal may be stronger. So yes, Rust-Oleum does stop rust when surface is properly prepared and primed, but it is not a substitute for removing heavy rust and fixing moisture source.