A writer has advised anyone wanting a brighter smile to save up for professional teeth whitening treatment in order to avoid damaging their teeth.
Miriam Stoppard told the Mirror DIY kits could "permanently damage your teeth and even harm your long-term health".
She pointed out that although kits used by professionals do contain sodium bicarbonate and hydrogen peroxide, dentists know what they are doing with the substances.
When these chemicals are used at home, they could damage tooth enamel, actually causing them to turn darker because the dentin below is exposed.
"If you want whiter teeth, ask your dentist's advice … save up money for a professional treatment that's guaranteed to work and be safe," Ms Stoppard urged.
This follows advice from the British Dental Association's Martin Fallowfield earlier this week, who told the Sun that kits bought on the internet or through beauty salons could be downright dangerous for teeth and gums.