CJC-1295 Pen vs Ipamorelin Pen
The growth-hormone research stack that everyone asks about.
CJC-1295 and Ipamorelin are almost always studied together — CJC-1295 is a growth hormone releasing hormone (GHRH) analogue, Ipamorelin is a growth hormone releasing peptide (GHRP), and the two stimulate GH release through different receptor pathways that potentiate each other. Researchers evaluating these two as separate purchases are usually deciding whether to start with one or run the stack from day one. ORYN ships both as dial-a-dose pens with <2% variance per click.
Scientific background
CJC-1295 is a GHRH analogue — it binds to the growth hormone releasing hormone receptor (GHRH-R) on the pituitary and stimulates the endogenous GH release pulse. Research investigates its role in GH pulse amplitude, downstream IGF-1 signalling, and potential effects on body composition and metabolic research. Ipamorelin is a selective ghrelin mimetic / GHRP (growth hormone releasing peptide) — it binds to the growth hormone secretagogue receptor (GHS-R) and stimulates GH release through a different pathway. Unlike older GHRPs, Ipamorelin has very low affinity for cortisol and prolactin receptors, which is the main reason researchers prefer it in long-term protocols. The two peptides together produce a synergistic GH release pulse that's larger than either alone.
When to pick which
BEST FOR CJC-1295
CJC-1295 is the usual starting point if the research focus is on GH pulse amplitude, IGF-1 downstream signalling, or any protocol where the GHRH receptor pathway is the primary interest. The smaller click increment (0.1 mg) makes it good for titration-heavy protocols.
BEST FOR IPAMORELIN
Ipamorelin is the usual starting point if the research focus is on the ghrelin mimetic pathway, selective GH secretion without cortisol or prolactin side-effects, or any protocol where the GHS-R receptor is the primary interest. Also a common choice for longer research protocols because of the clean receptor profile.
STACKING NOTE
CJC-1295 + Ipamorelin is the canonical GH research stack in the published literature. The two peptides target complementary receptors (GHRH-R and GHS-R) which produce a synergistic GH release pulse — larger than either peptide alone. Most research protocols run them concurrently, typically in the same subcutaneous injection site since the volumes are small enough to co-administer. ORYN pens make the concurrent delivery easy since you click each pen at the dose the protocol calls for and inject separately.
Full comparison matrix
| CATEGORY | CJC-1295 | IPAMORELIN |
|---|---|---|
| Receptor target | GHRH-R (growth hormone releasing hormone receptor) | GHS-R (growth hormone secretagogue receptor / ghrelin) |
| Pathway | GHRH analogue | Selective GHRP / ghrelin mimetic |
| Research focus | GH pulse amplitude, IGF-1 signalling | Selective GH release without cortisol/prolactin |
| Side-effect profile in literature | Well-characterised, classic GHRH effects | Very clean — low cortisol, low prolactin affinity |
| Cartridge size | 5 mg (30-day supply) | 5 mg (30-day supply) |
| Typical click increment | 0.1 mg per click | 0.1 mg per click |
| Dose accuracy | <2% variance per click | <2% variance per click |
| Stacking synergy | Better paired with a GHRP (Ipamorelin) | Better paired with a GHRH (CJC-1295) |
| Starting price | €109 EU · £89 UK · $119 US · R$549 BR | €109 EU · £89 UK · $119 US · R$549 BR |
VERDICT
These two pens are designed to be used together, not against each other. The research literature strongly supports the CJC-1295 + Ipamorelin stack because the two receptor pathways synergise to produce a larger GH release pulse than either peptide alone. If you're only going to buy one, choose based on which receptor pathway your research focus targets — GHRH (CJC-1295) or GHS-R (Ipamorelin). If your protocol is about total GH research output, order both from day one.
FAQ
Should I use CJC-1295 and Ipamorelin together or separately?
The published research literature strongly supports the stack — the two peptides target complementary receptors and produce a synergistic GH release pulse. Most research protocols run them concurrently. ORYN does not provide therapeutic guidance on human use.
What's the difference between CJC-1295 with DAC and without DAC?
DAC (Drug Affinity Complex) is a modification that extends half-life from hours to days by binding to serum albumin. ORYN's CJC-1295 Pen is the no-DAC form, which is what most research protocols use because the shorter pulse profile matches how endogenous GH normally releases. If your research specifically requires the DAC form, contact ORYN support about availability.
Can I inject both in the same session?
In the research literature yes — researchers typically administer both peptides in the same session, often via separate injection sites on the same area. The pen format makes this easy because each pen has its own dose dial and you can use one fresh needle per injection for full sterility.
Which one is cheaper?
Both pens are priced identically at €109 EU / £89 UK / $119 US / R$549 BR. Because they're usually purchased together as a stack, consider that total cost when budgeting — two pens together hit the free-shipping threshold in every major region.
Why Ipamorelin and not a different GHRP?
Ipamorelin is the most-selective GHRP with the cleanest receptor profile — very low affinity for cortisol and prolactin receptors compared with older GHRPs like GHRP-2 or GHRP-6. This is why Ipamorelin has become the default GHRP in research protocols that need long-term administration without confounding hormonal effects.
Order both and compare in your own lab
Every ORYN pen ships with a Certificate of Analysis, a 30-day money-back guarantee, and the pen-format mechanical accuracy (<2% variance per click) that makes direct comparison possible.