
Originally Posted by
einstein1905
Regular IGF-1 has a short half-life, but it's also dependent upon the levels of IGFBP3, as higher levels will make for a longer half-life of IGF-1. IGFBP3 protects IGF-1 from degradation but also prevents it from being able to readily bind its receptors. The LR3 version has a porcine (pig) region of GH, I believe, at the N terminal end of IGF-1, which serves as a pseudo IGFBP by not allowing it to be easily degraded...it also prevents actual IGFBPs from binding it. These additional amino acids do not, however, prevent LR3 from binding IGF receptors, so the half life actually is considerably longer...by how much, I don't know for sure.