My keto strips expire in one month. I’m on hour 60 of fast and still showing no ketones. Could they be expired early? Or another reason?
Keto strips aren’t perfect. Especially for people who are regularly in ketosis through diet or fasting, they might show low levels of ketones even if you’re in ketosis. After 60 hours, your glycogen stores are pretty well depleted and you aren’t eating anything to produce glucose, so you have to be in ketosis (or you’d be dead).
Given you’re only 60 hours in I would bet on #1 or #3.