I'm not new to bleaching, but I've never ordered online before. This stuff is the real deal. It's actually more potent than the ones I had been getting at the dentist (35% active bleaching ingredient, or less), and I paid $20 (employee discount) for 2 syringes that I believe were actually smaller than the syringes in this listing. So the value is as awesome as the results.
The staining I have isn't that bad, but I do drink a lot of tea, so bleach is more of a maintenance thing so my teeth don't get too yellow. Because the gel is more potent, the results I got after one use were twice as good as what I would have gotten from the gel I bought from my dentist with the same 15 minute treatment. In other words, I would need to bleach less for my personal maintenance.
I've been using an old ill fitting tray, so I have had a problem with burning on my gums in one area, despite not overfilling. That's my fault, but just as a caution that this will burn your gums and if it hurts, immediately rinse and stop using the product until your-completely- healed or else you're going to make your burns progressively worse.
The one negative thing I'll say is no syringe tips are provided. It's very difficult to fill your trays with the wide stubby end. I have some scaling instruments lying around so I've been able to use that to place the bleach in my tray where I want it, but they should include a few at least.