It depends on the product and treatment you choose as well as the type of tooth discoloration you have. The fastest results are achieved with in-office Opalescence Boost kit in 1 or 2 sessions through your dentist’s procedure. The take-home Opalescence PF whitening system may take more home sessions. With Opalescence Go whitening kit, it may take 5 to 10 days for visible results to appear. Finally, the whitening toothpastes offered by Opalescence may give you whiter and brighter teeth in less than a month.