I can find them at any major pharmacy around here--$10 for 50 stix. Mine range from very dark to medium, if I'm good. They turn VERY dark when I work out. I do wonder sometimes about the relationship between color and fat-burning. I've heard strong opinions on both sides. If there's no difference, then why is each color associated with a number (of ketone presence)? And is it possible to be in ketosis without losing weight? (I seem to be!) I'm confused...