I have sensitive teeth anyway, but this product did feel a bit uncomfortable on my teeth the second time I used it. The instructions say to use it for 10 days in a row, but I used it for the first time, took a few days off and did the second treatment and it was already slightly uncomfortable. Nothing too bad, but if I used it 10 days in a row I am sure it wouldn't feel good. It did seem to whiten a bit, and my teeth felt nice and clean afterward. It was easy to use except I didn't use the tray the second time and I "brushed" the gel on my teeth and that seemed to be less messy than the first time when I put the gel in the tray and bit down. That was messy and it just made me drool which seemed to just wash the gel away and I had to keep spitting during the process. Also, it says to avoid getting it on your gums, but there is literally no way to avoid this. The formula bubbles a bit with the light, and when it mixes with your spit it's getting everywhere in your mouth. Overall, I think this is a good product for the price, I just wish it didn't make my teeth sensitive, and that the formula stuck to teeth better and didn't just mix with spit and make a foamy mess in your mouth during use.

Read the reviews and the product was priced right - Have ordered this twice now and love the results it give me. I drink a lot of coffee and have poor enamel so my teeth get yellow relatively-quickly. While I've used other teeth whiteners before, this product has done so much better (with longer-lasting results) than those other products. I never had to use the included gel for sensitive teeth. Highly-recommended.

I'm not exaggerating here, as I don't write too many Reviews, unless I truly believe in the Product or the Company.
I have used tons of Teeth Whitening Treatments, White Strips, and also the expensive Whitening Process from the Dentist...., and I AM ABSOLUTELY AMAZED AT THE LUELLI WHITENING KIT.
I have very very sensitive teeth. I actually grind my teeth. And, many of my teeth are not only worn through the Enamel. But, my Dentist actually told me that some of my teeth are actually worn down to the Dentin. I didn't even know what Dentin was.

But, the point to this, is that every single Teeth Whitening Treatment I have tried in the last 5-7 years has given me so much pain and sensitivity that I had to stop the process a few days into it.

And, I honestly was thinking that there was no way that this LUELLI Teeth Whitening Kit was going to remotely work. Especially within the "claimed" 10 minute sessions.

All I can now say is WOWWWW!
I have used this treatment for only 6 days in a row, for only 10 minutes each time. (as I was concerned that the pain would come if I went for longer times).

AND, IM NOT EXAGGERATING AT ALL...., BUT IN 6 SESSIONS, MY TEETH ARE ALMOST 50% WHITER.(with only 10 minute sessions).
And, I've only had to use the
"Pain Relief Gel" once or twice. And, to be honest, it wasn't really necessary. The pain was minimal. But, I used the "Pain Relief" Gel, just in case the Pain got worse thru the night.
It didn't get worse at all!

I truly don't actually understand how this Whitening Treatment can work so well. All while using a very similar Hydrogen Peroxide Formula like all the Teeth Whitening Systems use. There must be some "Inactive" Ingredients that have been added to the Product, to produce synergistic results. Or, LUELLI has just produced the perfect amount and combination of ingredients that is also perfectly "activated" and enhanced by the Blue LED LIGHT (which I actually do have a vast knowledge of the different Wave Spectrums of Light and the Nanometer Wave Length that produce different benefits on the Human Body. I humbly own several
Health Spa's and Salons..., and we have many different
Light Therapy Treatments(from Blue Light, Red Light, Near Infrared Light, to Full Spectrum Far Infrared Light).
So, the Blue LED Light does definitely increase the results of any Whitening System. But, I've used it with other Teeth Whitening Treatment before.

And, I've never gotten these results before (without the intense pain).

UNLESS THE INCREDIBLE WHITENING RESULTS FADE AFTER 2 WEEKS OF STOPPING THE USE OF THIS PRODUCT...., this is the best product I've used in 20 years. (P.S. I did my Dentist's Whitening Treatment about 18 years ago. It worked! But, was soooo painful and expensive).

And, trust me, if the great results fade after 2 weeks, I will update my review.

I've also tried to add a picture, as I actually feel great "smiling" again in all my pictures now. But, my Phone is not letting Amazon access my Camera for some reason.

Amazing Product. 50% whiter teeth in 6 x 10 minute sessions, for 6 consecutive days.
I CANT WAIT TO SEE THE RESULTS AFTER THE RECOMMENDED 14 DAY USE.

I did see improvement in color & not so sensitive to my teeth though I hve very sensitive teeth

This product did an amazing job and i'm still going to continue to use it BUT if you have a sensitive gag reflex like me I would think twice. The mouth piece is genericly sized so it is huge for my 19 yr old mouth. Also the flavor is unpleasant but not unbearable so that's something to think about too. I have very sensitive teeth and this didn't cause any pain whatsoever so I would approve of this product 100% if it didn't make me want to throw up while I was doing it haha.