Actually, I don't even buy it. You are still young and an amateur. You should start with the usual nutrition and don't eat supplements. In other words, you should not take muscle gain as a myth. Muscle building is only one goal of fitness. If you don't believe me, there is no need to excessively increase muscle mass (which is directly related to the total intake of protein). There's nothing wrong with not taking supplements. Eat more eggs and beef, just like high-quality protein.