It depends on what kind of protein powder it is and whether you are doing professional fitness training. If you don't do professional fitness, don't eat it, because it will cause excessive burden of renal function, which may lead to renal failure and uremia.

Casein is the best protein for professional fitness before going to bed. Because it takes several hours to be fully digested, it can play a slow-release role in sleep, so that muscles can get enough amino acids during sleep.

From a scientific point of view, muscles will grow at the beginning of fitness, but it usually takes more than a month to see the effect, depending on personal situation and exercise intensity. The key to muscle building is to have enough strength and replenish enough protein. Drinking some protein powder after fitness at ordinary times is conducive to better muscle gain. Protein powder can be bought online, PQfitness.