Opalescence Go, step by step

Follow the directions inside your box first; this is a plain-English version.

Before

Brush and floss. Don't whiten if a tooth hurts or if your dentist has told you not to. If you're in a sensitivity plan, start your fluoride toothpaste two weeks ahead.

Wear

Open one upper and one lower tray. Seat the outer tray over your teeth, suck gently and remove the outer tray, leaving the thin inner tray in place. Wear 15 minutes (10% HP) as directed. Don't eat or drink while wearing.

After

Remove and discard the trays, brush gently or rinse with water. Avoid coffee, tea, red wine and tobacco for the next hour — ideally 48 hours.

How many days

5–10 consecutive days for most people; every other day if you're sensitive. Judge your result two weeks after you finish, not the next morning.

Stop and message your dentist if

One tooth hurts sharply, pain lasts more than two days after stopping, or your gums turn white where gel touched them (it fades; tell your dentist anyway).