We designed both the Stak and M-Stak to be "natural" anabolics. Yet each works in very different yet complementary way. In other words, you can use them separately, or "stacked" together.
Animal Stak is a natural hormone "enhancer". It works with your body to: (1) help "boost" key anabolic hormone levels and (2) enhance overall hormone function (such as improving the ratios of free to total testosterone). Stak, therefore, is a hormone modulator.
Animal M-Stak, on the other hand, works to help promote anabolism, not by manipulating hormone function, but by increasing important anabolic "processes", including protein synthesis, "nutrient partitioning" and nitrogen retention, all the while reducing muscle catabolism.
In short, Animal Stak can help with performance and strength. It can especially assist older athletes by helping to modulate hormone levels, which decline with age. Animal M-Stak, on the other hand, can help any lifter, but particularly the classic "hardgainer, by allowing him to gain lean mass and size more quickly and efficiently. It can help lifters on bulk looking to maximize lean muscle and minimize bodyfat, and help dieters hold on to precious lean mass.
Of course, you can combine the two to get the best of both worlds.
Both available at bodypro at 4000 each!!