35% with PF Gel Syringes Teeth Whitening - (8 Syringes) Refill Kit Carbamide Peroxide. Made by Ultradent, in Melon Flavor. Tooth Whitening Refill Syringes 5404-4

This item does whiten teeth is a short amount of time. My dentist made my trays a couple of years ago. Their products are expensive, but I found this whitener on Amazon. Works as well as the product directly from my dentist at a fraction of the cost. Highly recommended.

Bought this to try as it was a little cheaper than my Dentists of the same %strength. This worked better but was also a tiny bit irritating to my gums. Irritation was not bad at all as was gone between middle and end of next day. Irritation was only felt, gums a little deeper pink but nothing more. Will buy again when I run out. Note: I don’t bleach often, just every couple of months.

Couldn’t really tell a difference. I didn’t really stick with it. But my younger sister tried it and her teeth look stunningly white. And she’s a smoker. I was shocked. They really do look stunning. We’re both in our 50’s.

Been using this Opalescence 35% gel twice a week overnight in my Invisalign trays and—wow—this stuff works. As a card-carrying coffee addict, my teeth were starting to look a little too espresso-forward, but now they’re gleaming like I’ve never touched a latte. That said, 35% is no joke. Leaving it on for 10–12 hours definitely brings the brightness, but also brings the zing—hello sensitive teeth and slightly angry gums for a couple days. It’s like my mouth goes through a bit of a whitening boot camp, but hey, no pain, no pearly gain? Melon flavor is... interesting. Not bad, just kind of a weird moment when your mouth tastes like fruit salad while your teeth are turning snow-white. Would I do it again? Yep. Already did. Just maybe not right before a big bowl of ice cream.

Love this for my trays. Easy to use and is the same that my dentist had for twice the price.I usually whiten after a dental cleaning, really whitens well. It is pretty strong so if you leave it on too long, your gums will start to tingle and can burn some.Highly recommend for real results

Very easy to apply with pre-fabricated dental trays from my dentist office. Same product my dentist provided but cheaper. The product works as advertised whitening my teeth. Use once a month.

Great stuff!!!

It does work somewhat as far as whitening but as soon as I put it on with my Invisalign there was a foaming crackling sound and it was super uncomfortable and I wanted to take off the retainer straight away but I barreled through. Taking it off 25 min later I see my gums are white, swollen, and irritated. Probably won't get this strength again !