Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to provide a scientific opinion on a list of health claims pursuant to Article 13 of Regulation (EC) No 1924/2006. This opinion addresses the scientific substantiation of health claims in relation to “αS1-casein tryptic hydrolysate” and alleviation of psychological stress. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member States or directly from stakeholders. The food constituents that are the subject of the health claims are “lactium milk protein hydrolysate”, “lactium-peptide compound” and “hydrolysat de protéines de lait: milk protein hydrolysate concentrated with 1,7 % of alphaS1 decapeptide (=lactium)”. In the context of the references provided, the Panel notes that the food constituent which is the subject of the health claims is a specific commercial preparation of αS1-casein tryptic hydrolysate. The Panel considers that the specific αS1-casein tryptic hydrolysate is sufficiently characterised. The claimed effects are “helps to calm mind”, “mental state and performance”, and “stress”. The target population is assumed to be the general population. In the context of the proposed wordings and from the references provided, the Panel assumes that the claimed effects refer to alleviation of psychological stress. The Panel considers that alleviation of psychological stress might be a beneficial physiological effect. No references were provided from which conclusions could be drawn for the scientific substantiation of the claim. On the basis of the data presented, the Panel concludes that a cause and effect relationship has not been established between the consumption of “αS1-casein tryptic hydrolysate” and alleviation of psychological stress.