What formula do you supplement?

Katie

My baby is ebf but with my other children I have always kept formula on hand just incase. In the diaper bag and at home in the event she's starving and I cannot whip out a milk maker or have an emergency!

My baby is sensitive to lactose so I'm assuming Similac and Enfamil would upset her. What brands are you ladies who supplement feeding your breastfed babies and how did their tummies do when it was introduced?