Taking whey protein before bed can be an effective way to support muscle recovery and growth during the night, when your body is in a state of rest and repair. Studies have shown that consuming protein before bed can help to increase muscle protein synthesis and support muscle recovery, especially when combined with resistance exercise.
There is some evidence to suggest that slow-digesting protein sources, such as casein protein, may be more effective than whey protein for promoting muscle recovery and growth overnight, as they are absorbed more slowly by the body and can provide a steady supply of amino acids throughout the night.
However, it's important to note that individual needs and preferences will vary, and the best protein source for promoting muscle recovery and growth will depend on several factors, including your fitness goals, training schedule, and overall diet.