Overview
Growth hormone secretagogue research is a well-established domain within peptide science, with Ipamorelin, CJC-1295 No-DAC, and Sermorelin representing three of the most studied compounds in the GH axis literature. These peptides are distinct in their structure, mechanism, receptor targets, and pharmacokinetic profiles — making an understanding of their differences essential for researchers designing GH-axis studies.
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Ipamorelin in Research
Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) classified as a growth hormone-releasing peptide (GHRP). It acts as a selective agonist at the GHS-R1a receptor (ghrelin receptor), mimicking the effect of ghrelin — an endogenous peptide that stimulates pulsatile GH release from the anterior pituitary.
What distinguishes Ipamorelin in the research literature is its selectivity profile. Unlike earlier GHRPs such as GHRP-2 and GHRP-6, Ipamorelin was found in animal studies to stimulate GH release with minimal effect on cortisol and prolactin secretion — two off-target effects that complicate GH axis research with less selective compounds. This selectivity has made it a preferred tool peptide in GH axis research.
Key Ipamorelin research areas:
- Selective GHS-R1a agonism studies
- GH pulse amplitude investigation without cortisol interference
- Pituitary responsiveness models
- Comparisons with broader-spectrum GHRPs
Read our detailed Ipamorelin compound guide for full mechanistic context. Laboratory-grade Ipamorelin is available at our Ipamorelin 10mg product page.
CJC-1295 No-DAC in Research
CJC-1295 No-DAC (also called Modified GRF 1-29) is a synthetic analogue of the first 29 amino acids of endogenous growth hormone-releasing hormone (GHRH). It acts as a GHRH receptor agonist at the pituitary, stimulating GH release through the GHRH pathway — mechanistically distinct from Ipamorelin’s ghrelin receptor pathway.
The “No-DAC” designation distinguishes this compound from CJC-1295 with DAC (Drug Affinity Complex), which incorporates a lysine-maleimide linker for albumin binding and extended half-life. CJC-1295 No-DAC has a shorter active period, producing a GH pulse that more closely approximates the physiological GHRH stimulus. This makes it valuable for research designs requiring more controlled, pulsatile GH stimulation rather than sustained elevation.
CJC-1295 No-DAC research areas include:
- GHRH receptor activation studies
- Pulsatile vs. sustained GH release comparisons
- GH axis pharmacokinetic investigations
- Combined GHRH + GHRP synergy studies
See our CJC-1295 research guide for detailed mechanistic information. Our CJC-1295 No-DAC 5mg is available for qualified researchers.
Sermorelin in Research
Sermorelin (GHRH(1-29)-NH2) is the oldest of the three compounds in terms of research history. It is the amidated form of the first 29 amino acids of endogenous human GHRH, and was among the first GHRH analogues to undergo extensive clinical investigation, receiving regulatory approval in the United States for specific pediatric indications in the 1990s before being withdrawn from the market for commercial reasons.
Sermorelin acts via the same GHRH receptor as CJC-1295 No-DAC, but with a shorter half-life and without the structural modifications introduced in later analogues. Its primary research value lies in its historical literature base and its role as a reference compound for GHRH receptor pharmacology. Studies using Sermorelin in adult populations have examined pituitary reserve and somatotroph responsiveness.
Sermorelin research domains:
- GHRH(1-29) receptor binding studies (historical and current)
- Pituitary somatotroph function assessment research
- Comparison with longer-acting GHRH analogues
- Age-related GH axis decline investigations
Our Sermorelin 5mg is available for laboratory research purposes.
Research Distinctions
The three compounds differ across several important research dimensions:
| Feature | Ipamorelin | CJC-1295 No-DAC | Sermorelin |
|---|---|---|---|
| Receptor target | GHS-R1a (ghrelin receptor) | GHRH receptor | GHRH receptor |
| Peptide class | GHRP | GHRH analogue | GHRH analogue |
| Half-life (approx.) | ~2 hours | ~30 minutes | ~10-20 minutes |
| Selectivity | High (GH-selective) | GHRH pathway specific | GHRH pathway (short) |
| Research history | Modern GHRP literature | Modified GHRH literature | Extensive; oldest in class |
A notable finding in the research literature is that GHRP + GHRH combination approaches (such as Ipamorelin + CJC-1295 No-DAC) have shown synergistic GH release in animal models compared to either compound alone. This synergy is thought to result from complementary receptor mechanisms — GHRH receptor activation amplifies the pituitary’s sensitivity to ghrelin receptor signals.
For storage protocols applicable to all three compounds, consult our peptide storage guide. Visit our Research Hub for additional literature resources, or browse our research catalog for all available compounds.
For research purposes only. Not intended for human use. This content is educational and does not constitute medical advice.