Growth hormone research peptides fall into two groups. One group mimics growth hormone-releasing hormone (GHRH) and acts at the GHRH receptor: sermorelin, CJC-1295 with and without DAC, and tesamorelin. The other acts at the ghrelin receptor (GHS-R1a): ipamorelin. This hub explains how the two groups differ, how the compounds within each group compare, and links to the full research overview, comparison and Certificate of Analysis for each one.
All compounds discussed are sold for laboratory research use only. This page summarizes published research and is not guidance for human or veterinary use.
Two receptor pathways
Growth hormone release from the pituitary is controlled by two main signals. GHRH, made in the hypothalamus, binds the GHRH receptor on pituitary cells. Ghrelin, a hormone made mostly in the stomach, binds a different receptor, GHS-R1a. Research peptides in this area are built to act at one receptor or the other, which is why they are studied separately and, in some models, side by side.
| GHRH receptor | Ghrelin receptor (GHS-R1a) | |
|---|---|---|
| Natural signal | GHRH, from the hypothalamus | Ghrelin, mostly from the stomach |
| Research peptides | Sermorelin, CJC-1295 (no DAC), CJC-1295 (with DAC), Tesamorelin | Ipamorelin |
| Studied for | How GHRH receptor signaling and peptide stability shape GH release patterns | Selective GHS-R1a activation and its effects on GH and other pituitary hormones |
The GHRH analogs compared
All four GHRH analogs act at the same receptor. What separates them is length and the small structural changes that decide how long each one lasts in research models.
| Sermorelin | CJC-1295 (no DAC) | CJC-1295 (with DAC) | Tesamorelin | |
|---|---|---|---|---|
| Based on | GHRH(1-29), the shortest fully active fragment of native GHRH | GHRH(1-29) with four amino acid substitutions | The same modified GHRH(1-29), plus an albumin-binding group | Full-length GHRH(1-44) |
| Key modification | None (native sequence, C-terminal amide) | D-Ala2, Gln8, Ala15, Leu27 to resist enzymatic breakdown and oxidation | Maleimide “Drug Affinity Complex” that bonds to circulating albumin | Trans-3-hexenoyl cap on the N-terminal tyrosine |
| Duration in research models | Very short (minutes) | Short, but longer than sermorelin | Long, measured in days in human pharmacology studies | Short (a free peptide, not albumin-bound) |
| Research overview | Sermorelin research | CJC-1295 no DAC research | CJC-1295 DAC research | Tesamorelin research |
| Product | Sermorelin | CJC-1295 (no DAC) | CJC-1295 with DAC | Tesamorelin |
For a full side-by-side breakdown, including where each compound came from and how researchers choose between them, read Sermorelin vs CJC-1295 vs Tesamorelin: GHRH Analogs Compared.
Ipamorelin: the ghrelin receptor side
Ipamorelin is a five-residue synthetic peptide that activates GHS-R1a. Scientists at Novo Nordisk developed it in the 1990s, and the 1998 paper that introduced it called it the first selective growth hormone secretagogue, because in animal work it released GH without the broad hormonal spillover seen with earlier peptides of its type. That selectivity is the main reason it still appears in endocrine and receptor pharmacology studies.
Read the Ipamorelin research overview or view Ipamorelin.
Why CJC-1295 and ipamorelin are studied together
Because CJC-1295 (no DAC) acts at the GHRH receptor and ipamorelin acts at the ghrelin receptor, the pair lets researchers look at both pathways at once. Each component has its own preclinical literature, and the combination is studied as a blend for that reason. The CJC-1295 + Ipamorelin research overview explains what each component is and where the evidence stops. The blend is listed as CJC-1295 (no DAC) + Ipamorelin, and both peptides are also available as single vials.
Downstream: the IGF-1 axis
Growth hormone acts in part through insulin-like growth factor 1 (IGF-1), so IGF-1 analogs are often studied alongside GH secretagogues. Two engineered forms appear most often in research: IGF-1 LR3 and IGF-1 DES. See IGF-1 LR3 vs IGF-1 DES for how they differ.
What the research does not show
Most of the work on these peptides comes from cell, animal and small human pharmacology studies of hormone levels. That research describes how each compound behaves at its receptor and how long it lasts. It does not establish safety or benefit for any use outside the laboratory, and nothing on this page should be read that way.
Verify what you’re working with
Every batch is tested by an independent, ISO 17025 accredited U.S. laboratory. The Certificate of Analysis for the current batch is on each product page and in our COA Library, and the QR code on each vial label opens that batch’s report on the testing lab’s own website. New to lab reports? Read How to Read a Peptide COA.
Frequently asked questions
What is the difference between a GHRH analog and a GH secretagogue?
GHRH analogs, such as sermorelin, CJC-1295 and tesamorelin, act at the GHRH receptor. Growth hormone secretagogues in the ghrelin family, such as ipamorelin, act at a different receptor, GHS-R1a. Both lead to growth hormone release in research models, but through separate signaling pathways.
What does DAC mean in CJC-1295 with DAC?
DAC stands for Drug Affinity Complex, a maleimide group that bonds to albumin in circulation. That attachment is what makes the DAC version last far longer in research models than CJC-1295 without DAC.
Is sermorelin the same as CJC-1295?
No. Both are based on the first 29 amino acids of GHRH, but CJC-1295 has four amino acid substitutions that make it more resistant to breakdown. Sermorelin keeps the native sequence.
Are these peptides for human use?
No. All of them are sold for laboratory research use only. They are not for human or veterinary use, and nothing on this site is medical advice.
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Compounds researchers often order together, 5% off as a set. Every vial ships with its batch COA.
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