Universal Nutrition Animal M-Stak: Are you a true hard gainer? One of the unlucky few who hits the fork and food with extreme vigor and mass quantities but every time step on the scale it’s the same? It’s a problem when you’re trying to become larger than life and the reason could be that you’re not absorbing nutrients optimally. M-Stak is a nutrient practitioner that absorbs the nutrients needed to grow and disperses them to the muscle cells at an improved rate. In other words, you get a better bang for your buck out of your food with Animal M-Stak.