Kits to whiten your teeth at home, at a very low price. The concept is tempting and products are popping up on e-commerce sites. But beware, these kits present health risks, warns the association of British consumers Which? in a survey released on May 24.

Strips, syringes or pen

The association bought 36 teeth whitening kits from famous websites: Amazon, eBay, Wish and AliExpress. For each of these kits, experts measured the amount of hydrogen peroxide, the chemical used to whiten teeth.

Result: the majority of products contained levels of hydrogen peroxide above the authorized limit. And whatever the shape of the kit: in whitening strips, in pre-filled syringes or even in a pen with a brush.

Read also: These bad habits that damage our teeth and gums

21 products too dosed

More precisely, in France as in the United Kingdom, the current regulations stipulates that the concentration of hydrogen peroxide must not exceed 0.1% for products sold directly to consumers. In the test of Which?, 21 of the 36 products analyzed exceed this concentration.

The regulations also state that products containing 0.1 to 6% hydrogen peroxide are “reserved for dentists“. Dental products with a concentration greater than 6% are banned on European territory. Problem: 11 products out of 36 contain more than 6% hydrogen peroxide.

300 times too much hydrogen peroxide

The British association points to two products in particular: syringes filled with whitening gel called “Teeth bleaching gel kit” and “Sunup teeth whitening gel” sold on AliExpress, respectively by the sellers Oral orthodontic materials and Expsmile store. These two kits contain around 30% hydrogen peroxide, which is 300 times more than the maximum amount allowed for products for household use.

As for the products tested for which the concentration of hydrogen peroxide is below the limit, the quantity of this reagent is so low that the consumers’ association is questioning their possible effectiveness.

Burning of the gums and damage to the enamel

What are the health risks of over-dosed products? High levels of hydrogen peroxide can first cause burns in the gums, which will cause severe pain and may progress to gum recession.

But that’s not all: the chemical compound can also weaken the structure of the teeth and damage the enamel.

Two solutions at the dentist

What to do then? Do not buy dental products online because European standards are not necessarily respected. Instead, ask your pharmacist and dentist for advice.

The latter can offer you a whitening treatment, taking into account any contraindications. Two solutions are possible: a treatment in the office which lasts about two hours, or a treatment to wear at home, with a splint. Count for that between 500 and 1,800 euros.