Not all protein shakes are vegan. Some protein shakes are made with animal-derived ingredients such as whey protein or casein, which are both derived from milk. Vegan protein shakes, on the other hand, are made from plant-based ingredients such as soy, peas, brown rice, almonds, hemp, chia seeds, and more.
It is important to carefully read the label of any protein shake before purchasing to determine if it is suitable for a vegan diet. Many protein shake brands now offer vegan options, so it is becoming easier to find vegan-friendly options.