Protein shakes can be good for you when used appropriately, as they provide a convenient source of protein that supports muscle growth, recovery, and overall bodily functions like immune support and tissue repair. They are particularly beneficial for those increasing workout intensity, growing teens, people recovering from injury, or those on vegetarian or vegan diets needing plant-based protein options. Protein shakes can also aid in weight management by promoting fullness and preserving muscle mass during calorie restriction. However, they are not necessary for everyone and should not replace whole foods, which offer broader nutrients. Potential side effects include digestive issues, especially with dairy-based shakes in lactose-intolerant individuals, allergic reactions, and the risk of consuming protein powders with contaminants if sourced poorly. Overconsumption can strain kidneys, so intake should be balanced with individual needs and activity levels. For best results, use protein shakes from reputable brands in moderation as part of a balanced diet and exercise regimen.