Aptamil Pepti 1 800g Aptamil Pepti 1 Aptamil Pepti 1 is an extensively hydrolysed formula made with 100% whey protein. Suitable from birth, Aptamil Pepti 1 is formulated for the dietary management of cows' milk protein allergy (CMPA). Aptamil Pepti 1 is similar in composition to standard infant milks, apart from the protein which has been broken down (extensively hydrolysed) to make it less likely to cause an allergic reaction. It also includes lactose for improved taste, to help your baby enjoy each feed and support weight gain.