They sold this at my tanning salon for double the price on here. I noticed a difference after using for a month before my wedding. It was a huge crazy difference but my teeth were whiter, worth the $ and confidence of your smile on your big dayI am seriously AMAZED! I can't stop looking in the mirror. Did I say how beyond AMAZED I am?If you notice, most all the Bad reviews have to do with the faulty light. If you use a tanning bed it works awesome!!First, a few details about me. I have been a smoker for 32 years. I drink coffee daily. Hardly ever use a straw and love my Cherry Coke. NONE of which helps teeth look good. I have very sensitive teeth-Even Sensodine is sometimes irritating to my gums. I am a born skeptic but thought for under $20 what could I really lose buy trying this product. I am SO SO SO glad I did. I will be a repeat user for life. I did not use the little UV light it came with.MY PREP: I brushed my teeth and did a mouthwash before heading to tan. Still had my cigarette on the way though.I took a clean wash cloth from home to dry my teeth before application and a bottled water incase I had to rinse it out.TANNING BED APPLICATION:I used it 1 time last night during my 12 minute tanning bed session. (Not sure what "level" bed I was in. I just always use the one that browns and bronzes all at the same time-if that helps anyone)I dried my teeth, placed in the mouth piece , shook up the tube then applied very quickly but on all my teeth showing inside the mouth piece. I did it quick cause I new the bed was about to turn on. Lol In the future I may apply a coat before I leave the house and when I get there to make sure the inbetweens get covered. Then I tanned for 12 min.I took my lipstick off for the after pick because I didn't want my red lipstick making me think my teeth got whiter than they did but it wasn't necessary. No denying they were definately whiter.I put twilight teeth on after my lotion so it would be fresh going into the bed. HINT: At least have the brand new tube opened enough oily hands can open it or apply it before you get your hands oily.The mouth piece which looks odd but is comfortable. Just make sure to get your lips into the lip groove. Getting this product on your lips make them stickyish but does not burn or make them dry and crack.THE GOOD:Sensitivity: NO BURNING OR PAIN. JUST A LITTLE TINGLE.It did start to tingle some on my gums and I thought ok, here we go.I was prepared to wash it off but by the time I had it all applied and I got into the tanning bed it was done.SWALLOWING: NO WORRIES.Granted my tanning session was spent laying on my back.I didn't have alot of saliva occur and the little I did have I swallowedwith intrepidation. I tasted NOTHING. Whew. I have a bad gag reflex and was worried for no reason.THE BAD AND THE UGLY:NONE; My teeth looked and FELT great. Even today they still feel clean and look nice.I'm now a customer for life.I will update this review after I try the home UV light.******I WISH I could get the pictures to show but I can't get them to post. BIG BUMMER cause there is a HUGE difference.If someone knows how to get pics to post PLEASE let me know. I have never been so proud to tell about a product that stands up to what it says it does. ***********Would highly recommend this product, about to reorder one myself! I’ve only used this at home and I would still recommend laying back, the mouth piece is a little large so I drool if I’m sitting up. I noticed results after one use, however it did leave white spots on my teeth so I’d suggest using it before bed because they’ll be gone the next day. Had an issue with the battery not making contact properly at the bottom so I folded a small piece of paper towel and put it on top of the batteries in the compartment, then twisted the cap on and that added enough pressure for the light to work fine afterwards. Used this for 17-20min a day for 10days and my teeth were super white. If you have sensitivity, do it every other day and that should help. Also be careful not to get it on your inner lip because it will stick to your teeth and peeling them off creates a painful sore (only happened once). Just don’t do it for more than 14days at a time or more than once a year!I'am a teeth whitening Freak lol I have tried everything from home whiteners to the UV whiteners for tanning & I can tell you(my experience with it), It works but doesn't last long, Also you do not get a lot bottle very tiny, so for what you will spend to keep up using it when you tan you can buy the colegate strips for home, now yes I know there costly but you get a lot in each box & with them once you reach a desired color you stay that way for awhile & can stop them for a little bit & use a teeth whitening tooth paste in between. The Twilight whitening I didn't see that much of a big deal & the bottle is so so tiny & you have to use a lot on your teeth for each tanning session, so it's gone fast then you have to buy another. I will give you a little tip (as I'am a teeth whitening fanatic and tried everything) lol. For tanning & whitening your teeth you can buy the teeth pens in the drug stores or wallmart s or one called 5 minute tooth whitening gel -found in cvs or rite aid wallmart targets which is a few bucks & put that on before you tan and yu can use both at home with no light or with a light if you already have one & it works great. Keep up with them for a little bit & the color lasts longer than the twillight & they give yu a good amount of product that lasts forever and does even better for me. See any teeth whitener can work in a tanning session, my dentist told me that shhsss lol.. When i spent hundreds to get my teeth whitened I started trying other at home ones and found pretty good results with strips (for home only not tanning) & 5 minuite tanning gel & others but this id work but your color don't last, crest white strips & colegate strips last & others mentioned.I just wanted to share my experience but everyone is different. Good-luck & Happy Whitening!Received this today and used it right away’ easy to use! Love that the light clips in so it’s hands free! I seen a lot of reviews say light doesn’t work - you need to remove batteries and the small plastic insert - place batteries + up and then turn on! Can’t wait to take after pics!!I'd put a minus but you cant. Came and light doesnt even work! Waste of moneylight dont work flickers checked battery changed battery definitely a default and not worth the money very dissapointedEasy to use !Product itself it great.. but the batteries died within 8 minutes of the first use