Protein powder is a dietary supplement made from various protein sources, such as whey, casein, soy, or pea. It is commonly used by athletes and fitness enthusiasts to help meet their daily protein needs, support muscle growth, and aid in recovery after exercise. Typically available in powder form, it can be mixed with water, milk, or added to smoothies and baked goods. While it can be a convenient way to increase protein intake, it's important to balance it with whole food sources of protein, such as meat, fish, eggs, and legumes for a well-rounded diet.