You should results from blue shampoo after one use. Those with very brassy hair may take a little longer to notice a difference. If your hair is very brassy, try using it every other day, then switch to using it weekly for maintenance.
Picture this: you’re a brunette, excited to have highlights put in your hair, only to have a color that’s too orange for your liking. So you start to freak out and look for ways to fix it. Relax, breathe out. There’s always a solution.