IGF-DES 2mg

Des-IGF-1 is typically 10-100x more potent than native IGF-1 in in vitro cell culture assays, largely because IGFBP proteins are not present at physiological concentrations in cell media -- reducing this confound. In vivo potency differences are harder to quantify precisely because they depend on local IGFBP concentrations, which vary by tissue. The key point is that the reduced IGFBP binding makes a larger fraction of des-IGF-1 immediately available to bind receptors compared to native IGF-1, which is substantially buffered by binding proteins.

Des-IGF-1 has been found in human brain tissue and was first characterized from bovine colostrum. Its presence in the brain, where IGFBP-3 concentrations are lower than in plasma, makes sense for a form that doesn't bind binding proteins well -- the reduced IGFBP binding is less disadvantageous in a low-IGFBP environment. This distribution has made des-IGF-1 of specific interest for neuroscience research on IGF-1 receptor signaling in neural tissue.

Both are IGF-1 variants with reduced IGFBP binding, but they achieve this through different modifications with different characteristics. IGF-DES is a naturally occurring truncated form found in vivo, making it more physiologically relevant for studies of endogenous IGF-1 processing. IGF-1 LR3 is a synthetic long-acting variant with the additional N-terminal extension that further extends half-life beyond des-IGF-1. For studying natural IGF-1 truncation biology or brain-specific IGF-1 activity, des-IGF-1 is more appropriate. For chronic systemic administration studies requiring the longest possible exposure window, IGF-1 LR3 is generally preferred.