I don't know about any protein additives. However, I think the best protein shakes are Premier Protein. 4 different flavors, all good.: 160 Cal. 30g protein, 3 fat, 5 carbs. Best part is it tastes good and it's filling. I'm doing my 2 wk. clear liquid diet (plus the shakes) now. My surgery is scheduled for Jan 16th. Good Luck to you and God Bless.