CJC-1295 (without DAC) vs Sermorelin Acetate

CJC-1295 (without DAC)

CJC-1295 without DAC (also known as Modified GRF 1-29 or Mod GRF) is a synthetic 29-amino acid peptide analogue of growth hormone-releasing hormone (GHRH) with four amino acid substitutions (positions 2, 8, 15, and 27) that confer resistance to DPP-IV enzymatic degradation. Its mechanism of action involves binding to GHRH receptors (GHRH-R) on anterior pituitary somatotroph cells, stimulating cAMP-mediated signaling that triggers growth hormone synthesis and secretion. The amino acid modifications extend the peptide's biological half-life from under 10 minutes (native GHRH) to approximately 30 minutes, enabling meaningful GH pulse amplification while still preserving physiological pulsatile release patterns. Research on this modified GHRH analogue demonstrates it produces GH elevations within 15-30 minutes of administration, with return to baseline within 2-3 hours, mimicking natural GH pulse kinetics. Studies suggest CJC-1295 without DAC may support skin thickness and collagen production through GH-mediated IGF-1 elevation (Ionescu and Bhatt, Growth Hormone and IGF Research). Compared to the DAC-conjugated version (CJC-1295 with DAC), the non-DAC form produces shorter, more discrete GH pulses rather than sustained 7-10 day GH elevation, which some research protocols prefer for mimicking physiological patterns. It is frequently paired with ghrelin mimetics like ipamorelin for synergistic effect. Store lyophilized powder at -20C; reconstitute with bacteriostatic water and refrigerate at 2-8C for up to 21 days. This peptide is studied by endocrinology research departments, anti-aging medicine laboratories, and body composition research centers investigating GHRH axis modulation.

Sermorelin Acetate

Sermorelin acetate is a synthetic 29-amino acid peptide corresponding to the first 29 residues of the 44-amino acid human growth hormone-releasing hormone (GHRH 1-29). It represents the shortest fully functional fragment of GHRH capable of activating the GHRH receptor on anterior pituitary somatotrophs. Sermorelin was FDA-approved (marketed as Geref) for diagnostic evaluation of pituitary GH secretory capacity and was previously used in pediatric growth hormone deficiency research. Its mechanism involves GHRH-R binding, which activates adenylyl cyclase-cAMP-PKA signaling to stimulate GH gene transcription, synthesis, and pulsatile release. Clinical studies by Vittone et al. (Journal of Clinical Endocrinology and Metabolism, 1997) demonstrated that sermorelin administration in elderly subjects increased GH secretion and improved body composition markers including lean body mass and skin thickness. Importantly, because sermorelin works through the native GHRH receptor, GH release remains subject to somatostatin-mediated negative feedback, preserving physiological regulation unlike direct GH administration. Research has also explored sermorelin in cardiovascular contexts, where GH-IGF-1 axis activation may support cardiac tissue remodeling, and in seizure models where GHRH receptor activation appears to have neuroprotective effects. Compared to CJC-1295 (with or without DAC), sermorelin has a shorter half-life of approximately 10-20 minutes, requiring more frequent administration but producing very precise, physiological GH pulses. Store lyophilized powder at -20C; reconstitute with bacteriostatic water and refrigerate at 2-8C for up to 14 days. Sermorelin is studied by pediatric endocrinology research centers, geriatric medicine departments, and cardiovascular research institutions investigating GH axis modulation.

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