Gerber Baby Supplements, Probiotic Drops can be added to infant formula, see usage instructions below. Usage instructions  Use 5 drops once daily. Shake well before each use.  Turn the bottle to a 45°angle to slowly form a drop.  For babies, drops can be dispensed onto the breast, or added to breast milk or formula.  Drops can also be dispensed onto a sterile spoon.  No need to refrigerate. Just store below 25°C.