Birth to 12 months. Add water. Milk-free. Lactose-free. For fussiness, gas and spit-up. Use Similac Isomil to give your baby a strong start in life. An easy-to-digest soy formula for common feeding problems such as fussiness, gas and spit-up. Provides calcium for your baby's growing bones. Supports excellent growth during your baby's first year. Breast milk is recommended. If you choose to use infant formula, the makers of Similac have a formula that's right for your baby.