WASHINGTON, D.C.—With baby formula in short supply around the country, the American College of Emergency Physicians (ACEP) has a clear warning for caregivers: avoid watering down formula.

“Adding extra water to baby formula to try and make it last longer can put a child at risk of a seizure or another medical emergency,” said Gillian Schmitz, MD, FACEP, president of ACEP. “Given the current formula shortage, it may be tempting to look for a workaround, but it is very important to always mix formula according to the manufacturer’s instructions.”

Infants under the age of six months should not drink water or other liquids besides infant formula or breast milk, unless advised by a physician. Adding too much water to formula reduces its nutrient levels and could slow a child’s development. It could also cause an electrolyte imbalance that can lead to severe health problems, including seizures.

Baby formula should always be mixed as directed by the manufacturer, unless specifically guided by a physician or health care professional. 

With all sorts of risky homemade formula recipes on the internet or circulating among friends, the best choice is to talk with a physician about the safest ways to feed a child.

Feeding an infant under six months of age cow’s milk, or milk substitutes, is not a safe alternative to infant formula, emergency physicians said. Milk or similar dairy products can cause an infant severe illness at times of heat stress, fever or diarrhea.

Cow’s milk cannot be digested by an infant as completely or easily as formula or breast milk. It lacks the proper amounts of iron and other nutrients that infants need, which can irritate the linings of a still developing digestive system and lead to a dangerous electrolyte imbalance, bloody stool, or iron deficiency. Whole milk or toddler formula could be a temporary option for several days for a child older than six months if infant formula is not available.

“Actions that may seem like a harmless way to stretch the supply of formula could end up being dangerous,” said Dr. Schmitz. “An infant needs a careful balance of nutrients and even a brief disruption can cause health problems. Do not hesitate to bring a child to the closest emergency department for any concerns that they could be having a medical emergency.”