Gum irritation is a rather common reaction to whitening and is not serious. Luckily, there are some ways you can address this. In the event that you have gum irritation, we recommend taking a break from whitening for a few days to allow your gums to recover. You can swish with warm salt water to ease the discomfort. The key to minimizing the gum irritation is to avoid the whitening gel from having prolonged contact with your gums.
Make sure you are not putting too much gel into the tray. You only need a thin string of gel along the front, inner surface of the tray to get results. Too much gel will ooz out and sit on the gums.
Remove any excess gel that has spread onto your gums with a cotton swab or your finger + a tissue.
If irritation persists, rub Vaseline on your gums prior to inserting your trays. The Vaseline will act as a barrier so that less whitening gel is able to come into contact with your gums and irritate them.
Important: Always consult your dentist before using any teeth whitening product. If your gums bleed, this may be a sign of underlying dental issues. Cease using the product and consult your dentist.
Article on gum irritation