If you follow a really low carb diet, and you do the typical Keto, under 20 grams of total carbohydrates for an extended period of time, there have been some instances where there is a decrease in T3 thyroid hormone. Now, if you’re on thyroid medication and you’re optimized, then this is not a huge concern. These levels may show up as needing a little bit more medication. Maybe your free T3 goes below a 3.5 and we have to increase your dose, but typically that doesn’t happen as you naturally come out of ketosis anyway.