This is a randomized, controlled trial designed to evaluate a new strategy for promoting continued breastfeeding for mothers and babies who initiated breastfeeding in the newborn period. The new strategy, called Early Limited Formula (ELF), consists of 10mL of formula fed to each baby by syringe after each breastfeeding prior to the onset of mature milk production. The study intervention is discontinued at the onset of mature milk production, and the investigators will then follow mothers and infants for 12 months to assess the effect of ELF on breastfeeding duration, maternal experience and healthcare utilization.

Inclusion Criteria:

1. Full term, healthy singleton infant (≥ 37 0/7 weeks gestational age) in well newborn nursery
2. Exclusively breastfeeding (has not received any feedings other than breast milk)
3. Infant is 18-72 hours old
4. Infant has weight loss of ≥75th percentile on delivery mode specific nomogram documented at 12-72 hours of age
5. English-speaking mother

Exclusion Criteria:

1. Mothers or infants for whom breastfeeding is not recommended by the clinical team
2. Mothers who have already begun to produce mature breast milk
3. Any formula or water feeding prior to enrollment
4. Infants who have already lost ≥10% of their birth weight
5. Family with no active telephone number (home or cellular)
6. Plan for infant adoption or foster care
7. Mothers <18 years of age
8. Infant receiving scoring for Narcotic Abstinence Syndrome -