Fragment 176-191, Modified GRF 1-29, and Ipamorelin Blend: Adipose Metabolism, GH Axis Modulation, and Receptor Signaling Research

The Fragment 176-191, Modified GRF 1-29, and Ipamorelin peptide blend is a research-grade tri-component formulation combining three structurally and mechanistically distinct synthetic peptides. Fragment 176-191 (also designated hGH Frag 176-191, AOD-9604, or Tyr-hGH 177-191) is a synthetic C-terminal hexadecapeptide fragment of human growth hormone (hGH), engineered to isolate the lipolytic domain of the hGH polypeptide.^[1][5] Modified GRF 1-29 (CJC-1295 without DAC; tetra-substituted GRF(1-29)) is a structurally stabilized analog of the biologically active N-terminal 29-residue fragment of growth hormone-releasing hormone (GHRH), targeting the GHRH receptor (GHRH-R) on anterior pituitary somatotroph cells.^[6][9] Ipamorelin (NNC 26-0161) is a synthetic pentapeptide and selective agonist of the ghrelin receptor subtype GHS-R1a.^[10]

Each constituent operates through a pharmacologically distinct receptor system. Fragment 176-191 engages adipocyte metabolic pathways independently of the canonical hGH receptor and without measurable IGF-1 stimulation.^[12] Modified GRF 1-29 activates GHRH-R via Gαs-coupled cAMP-PKA signaling.^[6] Ipamorelin engages GHS-R1a via Gq/G11-mediated phospholipase C (PLC) activation and intracellular calcium mobilization.^[10] This tri-modal receptor architecture may support concurrent investigation of adipocyte lipolysis, pituitary somatotroph regulation, and ghrelin-axis pharmacology within a unified experimental framework.