I had seen a lot of celebrities using HiSmile, (celebs with lovely, white teeth.) So I thought I'd try it out.
I bought the set (3 syringes, LED light and the mouth guard), along with delivery to Northern Ireland, all came to $99 (about £47). I had to pay an extra $35 (£17) just to get it through customs!
The box that it all comes in is cute. I also like the LED mouth mould, it's a bit big for my mouth though. As for the gels, I find it hard to put on only a quarter of a syringe on each side. I ended up using more, just to get enough on the mould.
After the first week, there was a slight difference on one of my front teeth. Just a dot of white. It looked a bit strange, but barely noticeable. Other than that, it didn't work at all for me.
Soon after, I went on Amazon and bought 10 syringes of teeth whitener for £13 and free shipping. It sounded pretty much exactly like HiSmile, had some great reviews and it was REALLY cheap. The first time I used it, it made a BIG difference. It was awesome. And that gel was a lot thicker, so you could use less and still cover the mould.
In summary, HiSmile was very expensive and didn't work. I wouldn't recommend it.
Bottom Line: No, I would not recommend this to a friend