Similac is the #1 Infant Formula Brand Chosen by Moms† & the #1 Brand Fed in Hospitals Complete Nutrition for Your Baby's First Year Features OptiGROTM, Our Exclusive Blend of Important Ingredients Found in Breast Milk Similac Advance is a nutritionally complete milk-based iron-fortified infant formula, featuring OptiGROTM, our exclusive blend of brain & eye nourishing nutrients to support baby's development. Similac Advance is designed to support your baby's developing immune system, brain, and eyes, and to help build strong bones. Now available in a Non-GMO* option. Complete Nutrition for Your Baby's First Year The first year of life is a period of rapid brain growth. Help your baby reach important milestones with Similac® Advance® Stage 1 - an ideal first formula to help provide complete nutrition for your baby's first year.