What causes keto rash and how do you fix it?

By Dr. Stephen Phinney and the Virta Team

‍In our experience, ‘keto rash’ is relatively rare. In the cases we’ve seen, it tends to occur early in the course of a ketogenic diet when weight loss is rapid. Adding back enough carbs to suppress nutritional ketosis seems to resolve it, but weight loss also slows or stops.  Some people have reported that resuming nutritional ketosis caused the rash to recur, but in more mild form, and that eventually they could sustain nutritional ketosis in the 1-3 mM ketone range without any rash.  Unfortunately we have not had the opportunity to study this in an organized manner, and the cause is unknown.