Where workouts are concerned, Whey is considered fast acting and is perfect to take right after a weightlifting workout and is perfect for muscle growth.
Casein, though similar to Whey, is considered slow absorbing and usually taken at night right before so it can work to repair and build muscle while you sleep. Casein isn’t used in recipes or as a snack like Whey, but can actually be used as your protein in a full meal. Casein will keep you full longer and deliver a constant flow or protein typically over 5 hours.
If you are looking for a vegetarian protein powder alternative, Soy is usually where people turn first. Soy provides all essential amino acids and has been known to boost the metabolism and sparking fat and weight loss.