Whitening your teeth at home

The safest way to whiten your teeth at home in the UK is a kit prescribed by a dentist: custom trays and a peroxide gel, worn at home for around 2 to 6 weeks after an examination and a fitting appointment. UK practices list home kits from about £300 to £620. Whitening is not available on the NHS. In the UK it counts as dentistry, so only a registered dental professional can provide it. If you are having clear aligner treatment, ask the dentist moving your teeth before you whiten.

The options compared

The NHS says kits bought from a pharmacy or online, or whitening from places like beauty salons, do not work as well and may harm your teeth and gums.

Practice fee examples

Fees were checked on 22 October 2026 and are examples, not averages. Ask whether the fee includes the examination, trays, extra gel and top-ups.

The dentist-supervised journey

1. Examination. The dentist checks your teeth and gums and what kind of stain you have. Decay, gum disease, and a tooth that is dark because the nerve has died behave differently from ordinary surface stain. The NHS says whitening is not done on unhealthy teeth or gums, or if you are pregnant or breastfeeding.
2. Records. Impressions or a scan so the laboratory can make trays that fit closely, like a mouthguard.
3. Fitting. The NHS says you will usually have an appointment to check the trays fit, learn how often to wear them, and be shown how to protect your gums. For each whitening cycle, the first use must be carried out by a dentist (the regulations say a "dental practitioner"), or under that dentist's direct supervision; after that you finish the cycle at home. Separately, dental hygienists, dental therapists and clinical dental technicians can provide whitening treatment working to a dentist's prescription.
4. At home. You wear the trays with gel for around 2 to 6 weeks, as directed.
5. Review and top-ups. Results fade over time; a dentist can supply gel for later top-up cycles.

Sensitivity and side effects

The NHS lists teeth sensitive to cold or sweet food and drink, sore gums or throat, and white patches on the gums. These usually settle. NHS pharmacy guidance suggests a toothpaste for sensitive teeth, which your dentist may suggest putting in the whitening tray (not in orthodontic aligners), and fluoride mouthwash, and says to see your dentist if sensitivity is severe, or if pain lasts longer than a couple of seconds, which may have another cause. Teeth that are already tender from a new aligner are a reason to ask before you add whitening gel.

How long it lasts

The NHS says whitening is not permanent but may last around 3 years if you follow your dentist's advice. Coffee, tea, red wine and smoking stain teeth again; brushing twice a day and cutting back on those helps. Crowns, veneers, dentures, implants and white fillings keep their existing colour, so if only some teeth are restored, the natural ones can end up a different shade.

What to check, and the law behind it

• The person whitening your teeth is registered with the General Dental Council. You can check on the GDC website.
• You have been examined first.
• The gel is no stronger than 6% hydrogen peroxide, and you are 18 or over.
• The first use of each cycle is done by a dentist, or under a dentist's direct supervision. A hygienist, dental therapist or clinical dental technician can provide whitening on a dentist's prescription.

The General Dental Council's position, confirmed by the High Court, is that tooth whitening is the practice of dentistry whichever product is used, so only a registered professional can provide it as a treatment. Shops can sell products that contain or release less than 0.1% hydrogen peroxide. Products releasing 0.1% to 6% can only be supplied through dental professionals, and cannot be used cosmetically on anyone under 18; the exception is use wholly to treat or prevent disease. Charcoal, fruit and bicarbonate mixtures sit outside the regulated products a dentist uses.

While the aligners are in

Ask the dentist responsible for your aligner treatment before putting whitening gel in orthodontic aligners. Those trays are made to move teeth; a whitening tray is made to hold gel on the enamel and away from the gums.

Attachments, the small tooth-coloured bumps that help a tray grip, keep their own colour when the enamel around them lightens. A single case report of bleaching during aligner treatment found the enamel under them still lightened, because peroxide can pass through the tooth. Ask whether to wait until the attachments are off.

A foam or pen supplied with an aligner package is that company's extra; your whitening plan is the one a dentist prescribes after examining you.

After the aligners

Many people wait until the teeth are in their new position. If bonding or veneers are part of the plan, the dentist should decide the order: whitening gel can affect how well a later white filling or veneer bonds, and a veneer keeps its colour if you whiten afterwards. Bonding and veneers are compared in ways to straighten teeth, and what moving teeth can do in what clear aligners can and cannot treat.