Quick answer: CJC-1295 without DAC is a GHRH analog and ipamorelin is a selective GHRP. In preclinical research they are studied together because they act on two different receptors on the same pituitary cells, which is why combined exposure produces a larger, more pulsatile growth-hormone response in laboratory models than either alone.
Two compounds, two receptors
CJC-1295 (no DAC) is a modified 29-amino-acid analog of growth-hormone-releasing hormone (GHRH). Four amino-acid substitutions make it more resistant to enzymatic cleavage than native GHRH. Without the drug-affinity complex (DAC) modification it does not bind albumin, so its activity in the literature is short-lived and pulse-like rather than sustained.
Ipamorelin is a pentapeptide from the growth-hormone-releasing-peptide (GHRP) family. It acts on the ghrelin receptor (GHS-R1a). In the original characterization work it was noted for selectivity: it stimulated growth-hormone release in animal models without meaningful effects on cortisol or prolactin, which distinguished it from earlier GHRPs.
Why they are studied together
GHRH receptor activation and ghrelin receptor activation converge on the same somatotroph cells through different second-messenger pathways (cAMP for GHRH, calcium and PKC for GHS-R1a). Preclinical work with GHRH analogs and GHRPs has repeatedly shown a synergistic rather than additive release, with the combination preserving the natural pulsatile pattern. That pattern matters in research because continuous, non-pulsatile exposure produces different downstream signaling.
What the literature covers
- Receptor pharmacology and binding studies of each peptide separately.
- Animal and cell models measuring growth-hormone secretion in response to combined exposure.
- Stability and half-life comparisons between DAC and no-DAC forms of CJC-1295.
Handling notes for the bench
Both peptides are supplied lyophilized. Reconstitute with bacteriostatic water, refrigerate, and aliquot for anything beyond a few days. Because the two compounds are typically reconstituted separately and combined at the point of use in published protocols, keeping separate stock logs avoids concentration errors. Our peptide calculator handles the concentration math.
Sources
- Teichman SL et al. Prolonged stimulation of growth hormone and IGF-I secretion by CJC-1295, a long-acting analog of GH-releasing hormone. Journal of Clinical Endocrinology and Metabolism, 2006.
- Raun K et al. Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology, 1998.
- Bowers CY. GH releasing peptides: structure and kinetics. Journal of Pediatric Endocrinology, 1993.
All Browse Peptides products are supplied for laboratory research use only and are not for human or veterinary use. This article summarizes published literature for research reference and is not medical advice, a protocol, or a recommendation of any kind.