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Best Teeth Whitening Gels in the UK: Syringes, Pods, and More

Amanda Dexter
Amanda Dexter
Kristie Griebenow
Kristie Griebenow
Medically reviewed by
Dr. Sarah Abbas
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If you have whitened your teeth and want to keep your sparkly new smile, then you might want to know what the best teeth whitening gels used by dentists in the UK are. Or maybe you had your teeth professionally whitened by a dentist, and you want to maintain your smile at home.

Either way, if you've had your teeth whitened you'll want to keep them that way. You may only need to find more teeth-whitening gel for trays, or maybe you need to find a full whitening kit. There are plenty of whitening kits available, as well as whitening gel refill pods and syringes.

What are the best teeth whitening gels used by dentists in the UK?

The best teeth whitening gels used by UK dentists include Smile White, Opalescence and Boutique Whitening. These gels have active ingredients like carbamide peroxide or hydrogen peroxide and deliver noticeable whitening results. They are sold mainly through dental practices and are not typically available to buy over-the-counter purchase without dentist supervision.

However, you can purchase the Smile White teeth whitening kit online – our #1 recommendation⁣ – they give you 2 FREE Dentist appointments with a local teeth whitening expert, and guarantee brighter teeth for 3 years.

This article will discuss all of your options and answer the following questions, so you can keep your smile sparkly and your confidence high. 

Let’s get started so you can get on top of maintaining those pearly whites!

The following table summarises all of the products that we will discuss in this article: 

Best Whitening Gel

Smile White

  • Easy online ordering process, with pay in full or pay monthly with Klarna

  • FDA approved, fully safe products which whiten your teeth without causing damage

  • High-strength dental-grade 16% carbamide peroxide formula

  • Whitening gels come as part of a kit, with results that last up to 3 years

Smile Avenue Gel Refills 

  • Whitening ingredient is Phthalimidoperoxycaproicacid (PAP) for peroxide free whitening

  • Contains Hydroxyapatite (HAp) to strengthen teeth while whitening

  • 3 whitening gel pens 

  • Whitening gel applied directly to teeth

  • No sensitivity or irritation

  • Easy and controlled application 

Snow Whitening Wands 

  • 2-pack, 4-pack, 6-pack and 12-pack available to buy

  • Peroxide whitening

  • Whitening gel applied directly to teeth 

  • Designed for sensitive teeth 

  • Gluten-Free

  • Larger extra strength whitening serum also available

SmileTime Whitening Gel Refills

  • 3-pack

  • Whitening ingredient is Phthalimidoperoxycaproicacid (PAP) for peroxide free whitening

  • Whitening gel applied to trays/mouthpiece

  • Designed for sensitive teeth 

What is the best whitening gel in the UK?

The best teeth whitening gel in the UK is undoubtedly one that your dentist can use in-office or supply you with for a mixture of in-office and at-home whitening treatments. You can of course buy refills from your dentist, but they might be a bit more expensive. 

Fortunately, if you don’t want to pay dentist prices, quality at-home whitening kits and gels are available. 

So, let’s jump in with our top picks for the best whitening gels in the UK. We have included whitening kits for those of you that don’t already have one at home!

Smile White

smile white teeth whitening kit review

Smile White is a UK-based oral care company that provides professional treatments you can use at home. Their whitening gel comes as part of their whitening kit. Smile White partners with dentists all across the country to help patients get the treatment they need at an affordable price and without the inconvenience of multiple in-office visits.

To whiten teeth, the Smile White formula uses a combination of 16% carbamide peroxide and hydrogen peroxide. It has gone through rigorous testing and been found to cause absolutely no damage to gums or dental bone structure.

Smile White Pro Whitening provides custom whitening with bespoke trays and two in-office visits with a partnering cosmetic dentist. The fact that your treatment is supervised by a licensed dentist means that this system allows you to get safe professional whitening at home.

Smile White Pro changes the game by offering a kit developed and delivered by dentists, with results that last for up to 3 years.

Smile Avenue 

One of our top recommended tooth whitening gel and whitening kits is Smile Avenue. Their whitening gel comes in the form of gel pens which you paint directly onto your teeth rather than applying to a mouthpiece or tray. 

teeth whitening gel uk
Full control as you paint the gel onto your teeth

Smile Avenue whitening gel is a non-peroxide teeth whitening solution that uses the main ingredient PAP instead. PAP has been proven to have instant whitening effects and does not harm your enamel in the process. This whitening gel also has Hydroxyapatite as an ingredient, which helps to strengthen and remineralise enamel as you whiten your teeth. 

The whitening gel refills are available to buy separately, and you can buy 3 whitening gel pens for just £39.99. 

If you don’t already have a whitening kit, the Smile Avenue whitening kit comes with everything you need for a professional feel at home, including:

  • 4 whitening gel pens 
  • A shade guide
  • A mouth tray with built-in LEDs 
  • Adaptors to fit USB, USB-C and iPhone lightening sockets

This kit comes with 2 full courses worth of treatment, and when you run out, you can easily buy their refills if you wish to keep maintaining your whiter smile. 


The active whitening ingredient in Snow’s whitening gel is hydrogen peroxide. Snow is an American company so the percentage of peroxide used in the gel is higher than you can usually buy in the UK. 

hydrogen peroxide teeth whitening gel uk
Snow's whitening kit comes with 4 wands, or you can buy a standard or large refill wand

The whitening gel comes in the form of wands which you use to paint the gel directly onto the teeth before using your LED mouthpiece. In each kit you get 3 whitening gel wands and 1 extra strength whitening wand. 

When you run out you can order refills that come in standard and large sizes. The standard refill size gives you an average of 21 treatment sessions and the large, 42 treatment sessions. 

If you want to buy Snow’s full whitening kit, here’s what you’ll get:

  • ​​4 whitening gel syringes
  • 1 mouthpiece with LED technology
  • 3 whitening wands and 1 advanced whitening wand
  • 1 tooth whitening progress tracker
  • 5-year warranty
  • 30-day money-back guarantee

Snow has 2 different kits, the original and the wireless kit, which you can read more about in our full review. 


SmileTime's Teeth Whitening Refill Gels have been designed to deliver results in just 15 minutes, over a course of 6 days. 

They are formulated with PAP, the active whitening ingredient also present in both Hismile and Smile Avenue that whitens and brightens your teeth without any pain or sensitivity. 

teeth whitening gel
SmileTimes Whitening Gel Refills

Each set includes three 3ml gel syringes of the PAP formula, for six applications over a period of time.

If you want to buy SmileTime's Whitening Kit it comes with the following:

  • 6 x Applications of teeth whitening gel
  • 1 x LED Light
  • 1 x mouth tray
  • 1 x results chart 
  • 1 x instructions

You can read more about SmileTimes Teeth Whitening Kit in our full review, here.

Teeth whitening strips

Whitening strips come pre-gelled for your use, and there are a variety of brands that have them available, including Snow and Hismile.

Hismile’s PAP+ Whitening Strips are peroxide free and instead contain Phthalimidoperoxycaproic acid (PAP) as the active ingredient. Hismile's PAP+ formula is specifically formulated to not only safely whiten your teeth, but address pre-existing sensitivity and remineralise your enamel.

You can also check out some other whitening strip brands by reading our article on the best whitening strips in the UK

Why do you need whitening gel refills? 

mouth trays for whitening gel
Teeth whitening gel can help to maintain your pearly whites for longer after whitening treatment

If you have had your teeth professionally whitened, or you have whitened your teeth with a kit successfully, then you are probably wondering why bother with refills? 

Well, unfortunately, your beautifully white and stain-free teeth are not going to stay that way, especially if you like to drink coffee, red wine or other highly-pigmented food or drinks! But if you maintain your teeth after whitening, then they have a higher chance of staying white for longer. 

If you already have a whitening kit at home, getting refills for it is simple. You can simply order some more of the kind you already used. Or you can potentially use another brand of refills with the teeth whitening gel for trays you already own from your kit. 

If you had in-office whitening treatment with a dentist, you will likely be able to buy refills with your dentist if you still have your whitening trays. You may also be able to buy refills online to use with your whitening trays, but check with your dentist first. 

What are the different types of whitening gels available? 

When looking at whitening gel for teeth it is important that you know the different types. Some can cause sensitivity, and some can even damage your teeth enamel and gum tissue if you’re not careful. This can depend on the ingredients, and also the application method. 

teeth whitening at the dentist
Teeth whitening gels used by dentists have a higher percentage of peroxide in them

Whitening gel ingredients 

Most people associate whitening gels with including hydrogen peroxide as the whitening agent. However, there are some available with peroxide-free ingredients that are safer for teeth. Some commonly used whitening gel ingredients include:

Hydrogen peroxide is a well-known and effective whitening agent, but if used incorrectly it can damage your enamel and surrounding gum tissue. 

Teeth whitening gels used by dentists tend to have a much higher percentage of peroxide in them, but no more than 6% according to UK regulation. Over-the-counter whitening gels must also abide by UK regulations and can only have 0.1% or less hydrogen peroxide content. 

Some whitening gels are peroxide-free: HiSmile and Smile Avenue both use Phthalimidoperoxycaproic acid (PAP) which is much safer for teeth. These products also utilise ingredients like Hydroxyapatite which can help to remineralise your teeth while you whiten them. 

Types of teeth whitening gels 

Whitening gels not only come with different ingredients, but they can also come in different containers and styles. Some examples include:

  • Syringes 
  • Pods
  • Pens 
  • Strips

The different styles available can make a difference as some are messier than others, and some are safer for your teeth. If you already own a whitening kit you can use the refills with the mouthpiece, trays and LED lights that you already own. 

Whitening gels that come in the pen style involve the least mess and are safe for gums as you paint directly onto your teeth. Pods and syringes are simple to use as you just fill up your whitening tray and put it in to use.  

Strips aren’t used in conjunction with a whitening mouthpiece and LED light, but they do use a whitening gel that comes pre-applied. 

How do you apply the whitening gel to teeth?

Fitted trays for gel application

Different styles of whitening gel have different application methods; some are better for your teeth and gums, and some are easier to apply. 

Pre-gelled strips: These are possibly the easiest to apply as you just dry your teeth and stick on the upper strip to your upper teeth and the lower one to your lower teeth. Then you remove them after the directed amount of time. This can be a messy process and leave gel everywhere. 

It can also be difficult to keep the gel from getting on your gums which can cause damage to the tissue and irritation. 

Fillable mouth trays: These are a little less simple as they require you to fill them with a pre-measured amount of whitening gel from a pod or syringe. When you put the mouthpiece in your mouth you should get enough gel on your teeth to whiten them. But you may also get some on your gums.  

Gel pens: These require you to paint the gel onto your teeth, which is quite possibly the best method as you can make sure to get an even amount on your teeth and none on your gums. 

Here's a video on how to fill your custom trays from your dentist with teeth whitening gel:

How to use your dentist made custom made tooth whitening trays- a demonstration of putting gel in the trays and placing them in your mouth and some facts about tooth whitening and tips .


If you like your confident, pearly white smile after having whitening treatment then it's important to find a way to maintain it. Whitening gels can help you do this, and the good thing is you can buy refills for ongoing maintenance! 

smile avenue teeth whitening kit
Smile Avenue's Teeth Whitening Trays

There are quite a few different whitening kits and whitening gel types and styles on the market. The gels include whitening pods, pens, syringes and strips with pre-applied gel. There is also a choice of ingredients, some with hydrogen peroxide and others without. 

If you got your teeth whitened by a dentist, you can buy refills from them. However, our top pics for best peroxide free whitening gels in the UK is Smile Avenue. Their gels use PAP as the active whitening ingredient and other ingredients to strengthen your teeth as you whiten.

Snow is another good whitening kit that has gel pens that you use to paint the whitening gel directly on your teeth, or again you can just buy the refills. The whitening agent in this whitening gel contains hydrogen peroxide.

If you are interested in whitening kits then we recommend Smile White whitening kit – you can get 33% off your kit if you buy today. Or, if you are just looking for whitening gel, they all sell refills that you can use with trays or any whitening kit mouthpiece with LED lights.


Can you buy teeth whitening gels used by dentists in the UK?

You can buy teeth whitening gel from your dentist, but it may not be as strong as the one they can use in practice during in-office treatments due to UK regulations.

How do whitening gels work?

Teeth whitening gels contain active ingredients, such as carbamide peroxide or hydrogen peroxide, which penetrate the tooth enamel to break down stains and discoloration.

How long does it take to see results with teeth whitening gels?

Results with teeth whitening gels vary based on the product and where you got it from. Professional teeth whitening gels from dentists will have results much sooner than over-the-counter ones.

Can these gels cause tooth sensitivity?

Teeth sensitivity can be a common side effect of teeth whitening gels. However, you can find ones designed specifically to minimise sensitivity during and after whitening your teeth.

Best Teeth Whitening Gels in the UK: Syringes, Pods, and More
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GDC. Tooth Whitening Position Statement. Consulted 27st May 2023.