How to whiten your teeth safely at home, with a little help from a top dentist

We've seen some seriously dire things on TikTok in the teeth department recently. Users are taking their dental care into their own hands and, honestly, it's painful to watch.

One video, which has racked up over 12 million views, sees a teen applying hydrogen peroxide, a bleach commonly used in hair dye and fertiliser, directly to her teeth. Cue: a legion of dentists convulsing and some very unhappy gums for those jumping on board.

It's been labelled extremely dangerous by health professionals who warn that ingesting unregulated bleach could lead to tooth loss, lasting gum irritation and other problems.

Best avoided, then.

But, for those of us who want to give our teeth a spruce from home, what are the options? We asked dentists for their expert advice on how to achieve a whiter smile and to tell us everything we need to know about the whitening process. We've even put some of the most popular methods of teeth whitening kits to the test so you're well informed when it comes to selecting the right product for you.

So once you're done reading up on all things whitening, scroll down to see our reviews of the products you can try yourself at home from an organic DIY charcoal paste, to whitening strips.

So, how does teeth whitening work?

"Teeth whitening works by lightening teeth from the inside out," explains celebrity dentist Dr Richard Marques at Wimpole Street Dental (the man responsible for the smiles of Rita Ora and Binky Felstead). "The whitening solution usually contains either hydrogen peroxide or carbamide peroxide (although some methods do use other agents such as sodium perborate but these are generally considered less effective)."

"The peroxide solutions basically bleach or whiten the enamel, which is the outer covering of the tooth, and the dentine, which is the inside of the tooth. When both the enamel and dentine are bleached or whitened you get a much improved colour of the teeth that is usually sustained well for the long term," he says.

Do at-home teeth whitening treatments also use hydrogen peroxide?

"Clinics use hydrogen peroxide as well as home kits. Home kits can only use very very low levels of peroxide which is why they are not that effective. In clinic we are allowed to use higher concentrations as they are administered by a dentist, which gets much better results," says Dr Marques.

In UK (due to EU regulations) we use a 6% hydrogen peroxide solution (or up to 16% Carbamide Peroxide Solution as this is 3 to 1 of hydrogen peroxide so under 6% Hydrogen peroxide contained in 16% Carbamide Peroxide). In USA they can use 25% or more of hydrogen peroxide, however this can burn gums and cause sensitivity. These effects can be permanent so the teeth whitening in America is much more high-risk.

Is hydrogen peroxide safe for your teeth?

“The main reported side effect of teeth whitening is tooth sensitivity, but it’s important to remember that this should only be temporary,” says Dr Derek Swan, dentist and partner at New Town Dental Care. “If you do start to experience sensitive teeth, try brushing with a specially targeted sensitive toothpaste to help reduce this, and it should fade over time. Some patients also report a soreness of the gums, but again this should be a temporary effect that will subside. To avoid causing sore gums, make sure that you’re not using too much whitening gel in your at-home applications, and be sure to wipe away any excess gel from the gums, as this can cause soreness. If your symptoms persist, visit your dentist.”

Does LED light treatment actually work?

The whitening lamps used in clinics are of a very high grade so get very good effects but the LED lights at home are generally not of the same quality. It's the whitening lights that activate these whitening gels so it is important to have a good one. You can now buy at-home mini LED teeth whitening kits like the Hi Smile offering, which we reviewed here.

How white will my teeth go?

You would generally expect to see an improvement of 5-10 shades (on the teeth workout chart) from teeth whitening involving an in-clinic treatment. But according to Dr Swan, it's important to manage expectations. "Not everybody will achieve a Hollywood smile in one session,” he says. “Everybody’s teeth are different, and therefore they respond to treatment differently too. The thickness of your enamel will affect how well the whitening ‘takes’; if you have enamel wear, it will take more time for the teeth to whiten. Plus, if you have any fillings, bridges, crowns or implants, these will not whiten – you might have to consider having these changed after the whitening process if you’d like them to match your new smile.

How long will it take to whiten my teeth?

According to Dr Swan, the time it takes differs depending on the result that you want. "The in-clinic appointment for laser whitening often takes around an hour, but you’ll need to wear your trays for 30 minutes a day, for anywhere between three and 14 days after your appointment, depending on how white you’d like your teeth to be. For a naturally white smile, three days is sufficient.”

Will teeth whitening get rid of stains?

Stains on teeth can occur as a result of the enamel becoming discoloured when you have too much of highly pigmented foods or drinks like red wine and coffee as well as smoking tobacco. Whitening your teeth will help to remove stains but is important to have stained teeth cleaned first by a dentist or hygienist. If this is not done, the whitening gel will not be able to work fully and you could be compromising your results.

Are there any natural alternatives?

Some people swear by swilling coconut oil for whiter teeth or use activated charcoal in an attempt to remove stains. And while both can produce minor results, hydrogen peroxide is the most effective method.

What are the best at-home teeth whitening kits?

We've answered that one for you, here are our top picks...