Review Of How Long Can You Leave Toner In Your Hair 2023. Web in case of brassiness, you should keep the toner on brassy hair from 15 to 35 minutes. Web toner comes in all sorts of strengths, shades and sizes, but the general advice is that you should not exceed 45 minutes as you don't want your hair to be.
Web natural blondes with no prior bleaching: Web depending on the results you want, you can leave it for up to 45 minutes. You can leave color correcting shampoos on for five minutes before rinsing and conditioning.
