I went down the dentist route. Was around £300 I think and that was for the moulds and 4 syringes worth of gel. Made a noticeable difference using it overnight for a few weeks, going from one end of the scale to the other. Teeth became a little sensitive as a result but that wasn’t a long lasting thing. I just felt more comfortable going via my dentist instead of ordering strips from America or the like. I can get a “top up” every 6 months with my regular check up though once a year is probably enough if you don’t regularly drink teeth staining drinks. And that’s basically one syringe worth of gel for about £30.
i had philips zoom whitening done at a private well-rated clinic in bangkok thailand while i was out there (as it was cheaper) - dont recommend it though, didnt whiten my teeth that much and left them super sensitive for ages. my 2p/advice - dont worry about how white your teeth are
The wife gets some Colgate ones from America , small strips go on your teeth there a lot stronger than what’s allowed in the uk and the work great .
Don't be Ross (lol)
There was an older thread on Ask which recommended buying Opalescence syringes and doing your own moulds (can't find it now) though some HUKDers weren't keen on regular use of peroxide on gum enamel. Not to mention finding a reputable source. I've used Crest Whitestrips "Supreme" (they seem to be the best-rated, I've tried a few newer 3D White versions that weren't as good) though you'd have to buy them on import or from ebay. They definitely work, even first time. The problem with the strips is they don't cover every tooth, right to the back of your mouth (at least, not with me).