Healthy skin has a pH of 4.5 to 5.5, making it slightly acidic. This natural acidity protects your skin from harmful bacteria and other substances, so when this balance is disturbed - for example, by heat, cold, disease, cosmetics or stress - scalp sensitivity can occur. Eucerin DermoCapillaire pH5 Mild shampoo is specially designed to maintain the natural pH level of your skin, while also effectively removing impurities from your scalp and hair, preventing dryness and irritation. It removes dirt, pollen and allergens, and gives your hair a healthy shine and soft feel.