☰
NHS dentistsPrivate or NHSToothbrushesFlossingWhiteningCompare tools

Teeth whitening comparison tool: routes and a label checker

This tool does two jobs. First, it compares the main whitening routes available in the UK, from shop products to a dentist’s chair, on legal strength, cost, time and sensitivity risk. Second, a label checker takes the peroxide percentage printed on any product and tells you whether it can legally be sold to the public. It converts carbamide peroxide to the hydrogen peroxide equivalent for you.

We compare routes and not brands on purpose. We could not find independent, verifiable strength data for individual retail kits, and some product lists we saw disagreed about what the same kit contains. A label check you do yourself is more reliable than our guess.

Comparison tool

    Label checker

    Under the Cosmetic Products (Safety) Amendment Regulations 2012, as summarised by the Oral Health Foundation:

    • Products for the public may contain or release no more than 0.1% hydrogen peroxide.
    • Products above 0.1% and up to 6% can only be sold to dentists, who may use them after an examination, on people aged 18 or over, with the first application made by a dental professional.
    • Above 6% is not allowed for cosmetic whitening.

    Carbamide peroxide breaks down into hydrogen peroxide, and about 36% of its weight becomes hydrogen peroxide. So 0.1% hydrogen peroxide is about 0.27% carbamide peroxide, and 6% is about 16.5%. A kit sold to the public that lists 10% or 35% carbamide peroxide is above the public limit, whatever the box says.

    Watch out: The checker is a guide to the label figure only. It cannot tell whether a label is truthful. Do not use products above 0.1% hydrogen peroxide that arrive from an online seller, and ask a dentist about anything you are unsure of.

    Sensitivity risk by route

    The Cochrane review of home whitening found that mild to moderate tooth sensitivity and gum irritation were the most common side effects, and that strips and higher peroxide levels caused more complaints. The NHS lists sensitivity to cold or sweet food, sore gums or throat, and white patches on gums as possible effects. The tool shows each route’s sensitivity risk in plain words, and the full source notes are in our strips against dentist guide.

    Realistic results timeline

    • Shop products at 0.1% or less: we found no evidence that these change colour noticeably, and the Oral Health Foundation says they are too weak to.
    • Dentist home trays: the NHS says custom trays are worn for around two to six weeks.
    • In-surgery whitening: usually a single appointment of one to two hours.
    • How long it lasts: the NHS says around three years if you follow your dentist’s advice, and less with coffee, tea, red wine or smoking.

    Prices in the tool are rough ranges from 2026 clinic and directory guides. Ask any dentist for a written price for the whole course. If you cannot find a dentist, see our NHS access guide, and for what private care costs, see private against NHS.