Zanthan adds a little thickening for texture. It also reduces all tastes somewhat, including sweetness (slips right past those tastebuds if you put in a lot). Optional. I mix it in with my big powder batches so I don't have to add one more ingredient on a daily basis. If you do choose to add it separately into the blender each day, use only half as much! It's a more effective thickener before it's mixed with the other powders.Â