Your breast milk provides all of the nutrients and fluids that your baby needs. Usually, additional feedings of water or formula aren’t necessary. However, for a variety of reasons, some parents do choose to supplement breastfeeding with formula.

Most experts will tell you that formula or a bottle shouldn’t be given to your baby until she’s breastfeeding without difficulty and your milk supply is well established. This is usually two to four weeks after birth. A bottle introduced too soon, before your baby’s breastfeeding well, can have an adverse effect on your milk supply. Remember, supply equals demand. If your baby’s not nursing, or you are not pumping the milk, your body’s not being signaled to make more.