It is for infants that are salt wasters. Since they do not get enough salt in thier formula or breast milk they need to have it supplemented to them. They use it until table food is started.  This is a salt supplement. Not all insurance companies will pay for this to be made in the pharmacy. We needed it for my daughter as an infant. We mixed the salt solution in her formula. She drank it down in 2 ounces of formula, then I breast fed her the rest of her feeding.