Ipamorelin and CJC-1295 without DAC (modified GRF 1-29) are synthetic research peptides that are used together in experimental models to investigate the regulation of the growth hormone axis and the dynamics of pituitary signaling. Ipamorelin is a selective pentapeptide growth hormone secretagogue that acts as an agonist of the growth hormone secretagogue receptor (GHS-R1a), activating Gq/PLC- and calcium-dependent signaling pathways involved in GH release, while it shows only minimal interactions with other pituitary hormones in preclinical systems. CJC-1295 without DAC is a stabilized analogue of the growth hormone-releasing hormone (GHRH 1-29), which activates the GHRH receptor and stimulates adenylyl cyclase- and cAMP-mediated signaling pathways in somatotroph cells. Preclinical research uses the combined activation of GHS-R1a and GHRH receptors to investigate synergistic somatotrophic signaling, hypothalamic–pituitary feedback mechanisms, and peptide-mediated endocrine regulation.