You’ll likely feel a difference right away. The moment you put our shoes on, there’s an immediate sense of relief, that feeling of your feet being supported.
That said, if you have flat feet, your body might not be used to this kind of structured support. In that case, your foot may need a short break-in period, nothing dramatic, start with just a few hours the first day, then gradually add more as your foot gets more used to it. Most people adjust by the end of the week and often sooner. Once your feet adapt, the support feels natural and comfortable.