:In researching many of the teeth whitening products here on amazon(.)com and .ca, it looks like most of them are either 35% Carbamide Peroxide or 3% - 10% Hydrogen Peroxide … many of the other teeth whitening gels or pens just plain don’t even tell you what they contain. One of my google search results showed: The main difference between hydrogen peroxide and carbamide peroxide is that hydrogen peroxide is an effective whitening agent by itself. On the other hand, carbamide peroxide contains hydrogen peroxide in it. For every 30% of carbamide peroxide, there is also 10% of hydrogen peroxide. Additionally, Hydrogen peroxide breaks down faster than carbamide peroxide, so it releases most of its whitening power within 30–60 minutes. Carbamide peroxide, on the other hand, releases about 50% of its whitening power in the first two hours and can remain active for up to six additional hours. Personally, I find both equally as effective and I don’t have a preference either way.This product really covers all of the bases and here’s why:It comes with three 5mL whitening gel syringes and one 5mL (blue) Remineralizing and Desensitizing gel syringe. It also includes: 1 universal mouth tray – which means anyone can use it; 2 moldable teeth trays so you can mold them to your own teeth, a lightweight LED light device with a carrying case. See my pics. BEST OF ALL there are three ways that you can use this system:1: you can use it with the universal tray (one set for you and one for your spouse?)2: you can use it with the molded tray3: you can use it *without* a tray and just apply the gel directly to your teeth and use the light **HELFUL HINT: the brochure says you can use a Q-tip to apply the gel to the teeth, however, I prefer to use a very small makeup brush as I find it more precise. SEE PICTURESRe: Remineralize and Desensitizing (R & D) GelI found there wasn’t adequate information in the brochure about the R & D gel, so I looked through the customer Q & A’s … lots of people were asking about it. They were all as confused as I regarding the fact that the package contained 15 mL total of whitening gel and only 5 mL of R & D gel. So I sent an email to the address in the brochure and this is the response:—————————————————————————————————-To answer your question, not everyone is sensitive to whitening gels,the blue gel is not required for everyone.Furthermore, after the first or second treatment, your teeth havebecome used to the whitening and the blue gel is no longer required.Ok … that answers the question of Desensitizing, but what about Remineralizing? Well, after a little more research I found that there are a few things that you can naturally do to increase remineralization, like ‘produce more saliva (chew sugar-free gum), improve diet, avoid acidic food and drinks, etc., but most importantly, use a toothpaste that helps to remineralize teeth like Sensodyne Pronamel. As a matter of fact there is a great article on their website about Remineralizing teeth. Amazon does not allow reviewers to post outside links so just google: 6 Ways to Help Remineralize Teeth.Taste:The taste/flavor did not bother me at all.Sensitivity:I have receding gums (hereditary) and sometimes my teeth get a little sensitive, but this product did not bother me at all. Yes, I did feel a bit of tingling, but it did not hurt or irritate my gums. I alternate my toothpaste Colgate Optic White and Sensodyne which helps a lot.Viebeauti Customer Service:Excellent! Considering I reached out via email on Friday (Easter weekend), and received a very kind response bright and early Monday morning with answers to my questions about the blue gel, and with an apology for not responding more quickly because they were closed over Easter. 10/10 for CS.TIPS AND TRICKS1. If using this product without the trays use a tiny makeup brush. This will help you avoid your gums. SEE PICTURES2. I am notorious for clenching my teeth and it gives me a headache. So to avoid having to tighten my lips and clench my teeth so much to keep the light positioned, I fashioned myself a kind of ‘holder’ by making a small slice in a hairband (just large enough to secure the light). SEE PICTUREYou may not need anything like this but it sure make my life easier.3. If the back of your teeth are badly stained as well, your might want to consider doing what I did … apply about 3mL to the front portion of the tray and about 2mL to the back portion. The back of my teeth are now just as sparkling white as the front.4. You *can* eat after a treatment, just DON’T eat anything that would stain your teeth for a few hours. For example, you can drink water, milk, 7-up, etc, and eat non-staining foods … apples, turkey sandwich, etc., BUT AVOID: coffee/tea, red wine, Coke, blueberries, spaghetti sauce, etc. I’m sure you get it! In closing, I want to say that I highly recommend this product. It has worked very well for me and I will continue using it. SEE BEFORE AND AFTER PICTURES.So FULL DISCLOSURE … this is NOT the first whitening product I have used.- Colgate Optic White PEN. I really liked that a lot and found it worked well.- Plus White 5 Minute Speed Whitening Gel. I also liked this one as well and it is the least expensive of them all. It does whiten nicely. No complaints.- AsaVea Teeth Whitening Pen – the thing that irritated me was that neither on their product description page nor in the product brochure did they mention the ingredients. I had to google it and found the answer on the Walmart product page and on the AsaVea website but the packaging is different, so it just makes me wonder … ???- THE BEST SO FAR: VieBeauti Teeth Whitening Kit *My before and after pictures were taken after the above products were used but not before VieBeauti was used and the AFTER picture was used after 3 treatments of VieBeauti. I WAS EVEN SHOCKED WHEN I COMPARED THE PICTURES … which are not edited in any way other than cropping. This product did the most whitening and the fastest whitening.***This review was not solicited nor have I had any communication with the seller other than the answer to my question. I have profited in no way whatsoever for this review.***