Protein shakes are not inherently bad for weight loss, but it depends on how they are used in the context of an overall diet and lifestyle. When used appropriately, protein shakes can be a helpful tool for weight loss as they can provide a convenient source of protein, help increase satiety, and support muscle growth. However, if they are used in a way that adds extra calories to the diet or if they contain low-quality ingredients, they can interfere with weight loss efforts. It's important to choose a high-quality product that is low in calories and free from artificial ingredients and to limit your overall calorie intake. Consult with a doctor or a registered dietitian for personalized recommendations based on your individual needs and goals.