There's also a great article here by our Doreen T called Ketosis and Ketone Test Strips. It's in "Low Carb Tips" on the orange bar at the top of the screen.

Personally, I find them to be a waste of time and money. Too often inaccurate, and if I had a dollar for every time I've read some post that someone worried they are doing something wrong because their stix won't change colour - despite the fact they are losing weight beautifully, I would be one rich girl!

Cheers,

Roz