How does IGF-1 LR3 work?

IGF-1 LR3 is a modified analogue of insulin-like growth factor 1. An arginine substitution and an N-terminal extension reduce binding-protein affinity so it can stay active longer. This site's profile says it activates the IGF-1 receptor. Half-life is about 20 to 30 hours. Molecular weight is 9,111 daltons. This site's review found no published human trial. The citations on that page are animal work: LR3 IGF-I was about 2.5-fold more potent than native IGF-I at reversing catabolism in dexamethasone-treated rats; four days of infusion in pigs decreased daily gain, food intake, plasma GH, and endogenous IGF-1; and muscle-restricted IGF-1 expression in mice produced persistent hypertrophy into old age. Those animal findings do not transfer into a counted human muscle result. It is not FDA approved and is prohibited in sport at all times. This FAQ does not invent a human mechanism. Full record at /compounds/igf-1-lr3.

Educational use only. This database summarizes published research and is not medical advice. Where a dose appears it is a record of what a trial or clinic ran, or what people describe doing, with its source attached. Nothing here is a recommendation for personal use.

Part of growth hormone secretagogues. Sermorelin, tesamorelin, ipamorelin, CJC-1295, and the rest of the GHRH and ghrelin receptor family.