Cell Divison
Like IGF-1, IGF1-LR3 is a potent stimulus for cell division and proliferation. Its primary effects are on connective tissues like muscle and bone, but it also promotes cell division in liver, kidney, nerve, skin, lung, and blood tissues. IGF-1 is best thought of as a maturation hormone because it not only promotes cell proliferation, but differentiation as well. IGF-1 causes cells to mature, in other words, so that they can carry out their specialized functions.
Unlike IGF-1, IGF1-LR3 remains in the bloodstream for long periods of time. This property makes IGF1-LR3 a much more potent molecule. A dose of IGF1-LR3 provides approximately three times as much cell activation as a similar dose of IGF-1. Note that IGF1-LR3 and all IGF-1 derivatives do not promote cell enlargement (hypertrophy), but rather promote cell division and proliferation (hyperplasia). In the case of muscle, for instance, IGF1-LR3 does not cause muscle cells to get larger, but it does increase total numbers of muscle cells.