Yes, McDonald's uses real milk in many of its products.
McDonald's has stated they use fresh dairy milk in their ice creams, milkshakes, and McFlurry desserts. However, they use milk powder in a small number of products, such as chocolate muffins and chocolate brownies.
Therefore, while not everything at McDonald's contains fresh milk, the milk used in prominent menu items like ice cream and milkshakes is real dairy milk.
