The Similac Advance Stage 1 and Stage 2 formulae are made to help babies at various stages of development. While Stage 2 is designed for babies six months and up, supplying increased quantities of calcium, protein, and vital vitamins to support growth and bone health, Stage 1 is designed for newborns up to six months, providing key nutrients for early development. Age-appropriate nourishment is provided at each stage to meet your baby's evolving needs.