I have about half a packge of these from several years ao. I think they expired in like '05. I had used one last night and no change, then I used one today and it just turned the lightest pink. Would you trust it, since I have had only mean, eggs, and cheese for about 48 hours, except for a banana. I don't know about anyone else but those silly little sticks were a huge motivator for me when I was doing Atkins seriously years ago.
I need to get back to re-reading the book. night all!