Sermorelin vs CJC-1295 — same parent, different half-life
Sermorelin and CJC-1295 are both modified versions of GHRH(1-29) — the active fragment of growth hormone-releasing hormone. They share the same receptor (GHRH-R) and produce identical downstream effects. The differences are entirely structural: sermorelin is essentially native GHRH(1-29) with mild stabilisation, half-life ~10-20 minutes. CJC-1295 incorporates four amino acid substitutions (D-Ala², Gln⁸, Ala¹⁵, Leu²⁷) for protease resistance, extending half-life modestly. The DAC version (drug affinity complex) adds a maleimide group that covalently binds serum albumin, extending half-life to ~6-8 days — meaning weekly dosing in research protocols. Functional effect on GH release is similar at adequate dose; the choice between them is about dosing frequency and protocol design.
Side-by-side
| sermorelin-5mg | CJC-1295 (with or without DAC) | |
|---|---|---|
| Parent peptide | GHRH(1-29) — native | GHRH(1-29) — modified |
| Modifications | Acetate salt | 4 AA substitutions (+ DAC: maleimide) |
| Half-life | ~10-20 min | No-DAC: ~30 min · DAC: ~6-8 days |
| Research dosing frequency | Daily SC | No-DAC: 1-2× daily · DAC: 1-2× weekly |
| GH release pattern | Pulsatile (preserves natural rhythm) | No-DAC: pulsatile · DAC: sustained |
| Approved status | Was approved 1997-2008 (US, withdrawn for commercial reasons) | Never approved — development abandoned 2007 |
What to know
- ·Sermorelin is the closest research compound to native GHRH — same receptor, same pharmacology, just slightly more stable.
- ·CJC-1295 with DAC is what most people mean when they say 'CJC-1295' — the long-acting version with weekly dosing.
- ·The 'no-DAC' version of CJC-1295 has half-life similar to sermorelin and is essentially a slightly more stable sermorelin equivalent.
- ·GH release pattern matters: pulsatile (sermorelin, no-DAC CJC) preserves natural feedback loops; sustained (CJC-DAC) doesn't.
- ·Both research-use only. Sermorelin was previously available as Geref but is no longer marketed.
Where the literature diverges
Sermorelin's clinical literature is older (1990s-2000s) and includes paediatric short-stature trials. CJC-1295's clinical literature is thin — ConjuChem abandoned development in 2007 after promising phase 1 data. The compound is now research-only and most published evidence is animal-model. Researchers choosing between them typically choose sermorelin for clinical-comparable physiology, CJC-1295 for extended-interval dosing in animal-model work.
FAQ
Is the long half-life of CJC-1295 with DAC desirable?+
Debated. Sustained GHRH receptor activation produces continuous stimulation of GH release rather than the pulsatile pattern characteristic of healthy physiology. Some research argues sustained activation may eventually desensitise the receptor or disrupt downstream feedback. Others argue continuous activation is functionally equivalent at the IGF-1 level. No definitive trial data resolves this.
Can I use them interchangeably?+
Functionally similar at receptor level. Practically: sermorelin requires daily SC injection, CJC-1295 with DAC requires weekly SC. Choose based on dosing frequency tolerance.
This is a research-context comparison of compound mechanism and published trial outcomes. Not medical advice. Both compounds are research-use only when sold by Omega Grade — for in vitro laboratory investigation, not human or veterinary administration.
- ResearchCJC-1295 with DAC 5 mg
CJC-1295 with Drug Affinity Complex (DAC) — an extended GHRH analogue designed for half-life extension through covalent albumin binding.
- ResearchCJC-1295 no DAC 10 mg
CJC-1295 without DAC — short-acting modified GRF(1-29). Commonly used in preclinical GH-pulse research alongside ipamorelin.
- ComparisonTesamorelin vs CJC-1295 — GHRH analogues compared
Tesamorelin is FDA-approved; CJC-1295 is research-grade with longer half-life. The mechanisms, half-lives, and where the literature favours each.
- ResearchIpamorelin 10 mg
Ipamorelin is a selective ghrelin-receptor (GHSR) agonist. One of the cleanest pharmacological profiles in the growth-hormone-secretagogue class.
- ComparisonIpamorelin vs Sermorelin — GHS vs GHRH research
Ipamorelin is a GH secretagogue (ghrelin receptor); sermorelin is a GHRH analogue. They activate complementary pathways — what the research literature shows on each.