Long arginine 3-IGF-1, abbreviated as IGF-1 LR3 or LR3-IGF-1, is a synthetic protein and lengthened analogue of human insulin-like growth factor 1 (IGF-1).[1][2] It differs from native IGF-1 in that it possesses an arginine instead of a glutamic acid at the third position in its amino acid sequence (arginine 3), and also has an additional 13 amino acids at its N-terminus (MFPAMPLLSLFVN) (long), for a total of 83 amino acids (relative to the 70 of IGF-1).[2] The consequences of these modifications are that IGF-1 LR3 retains the pharmacological activity of IGF-1 as an agonist of the IGF-1 receptor, has very low affinity for the insulin-like growth factor-binding proteins (IGFBPs), and has improved metabolic stability.[1][2] As a result, it is approximately three times more potent than IGF-1,[3] and possesses a significantly longer half-life of about 2030 hours (relative to IGF-1s half-life of about 1215 hours).[4] IGF-1 LR3 Peptide is under active investigation in a number of cell culture and animal models
Growth hormone (GH) profiles in response to continuous subcutaneous infusion of GH-releasing hormone(1-29)-NH2 in children with GH deficiency
M., & Chen, C
At 29 amino acids, sermorelin is significantly larger than the molecules that absorb reliably through sublingual mucosa
GHK-Cu: Addressing Loose Skin Concerns Loose skin represents one of the most frustrating outcomes of significant weight loss
When administered alone, Ipamorelin promotes significant increases in GH and IGF-1, enhancing lean body mass and reducing fat without affecting other pituitary hormones. Kasselberg et al., Neuroendocrinology Letters This makes it a smart option for first-time peptide users , athletes in a cutting phase , or those prioritizing safety and moderate progress over maximum anabolic stimulation
