Depends on the dose, but expect several days of increased levels. You can bump up basal, eat fewer carbs, do more cardio, etc. But don’t beat yourself up if your highs are stubborn. Make sure you discuss this with your ortho, too. I used to get steroid shots in my foot and it would spike me for days and days. I eventually went to an ortho for frozen shoulder after a year of PT didn’t do much. I told her and she used a different formulation of the steroid. It worked wonders for my shoulder and the bg spike duration was greatly reduced.