fifteen minutes or until nothing comes out. if you're wanting to produce more milk you need to completely drain the breast so it signals your body to make more.

15 min is a good amount of time , even after 10 if nothing is coming out keep pumping another 5 it will tell your body to make so much for supply . You don't want to do more than 15 because you can over pump

are you pumping before or after a feeding?