CJC-1295 vs MK-677 (Ibutamoren)
CJC-1295 (GHRH analog (long-acting, with Drug Affinity Complex / DAC)) and MK-677 (Ibutamoren) (Orally active non-peptide growth-hormone secretagogue (ghrelin-receptor agonist)) are documented as co-studied in the PeptiDex library. This page puts the two entries side by side on class, molecular weight, half-life, origin, mechanism and studied research areas — every value taken from the entry it belongs to.
Why these two are co-studied
Cross-referenced for research context — not a usage or combination recommendation.
At a glance
| Attribute | CJC-1295 | MK-677 (Ibutamoren) |
|---|---|---|
| Compound class | GHRH analog (long-acting, with Drug Affinity Complex / DAC) | Orally active non-peptide growth-hormone secretagogue (ghrelin-receptor agonist) |
| Research category | Growth & GH-Axis | Growth & GH-Axis |
| Length (amino acids) | 30 amino acids | Not documented |
| Molecular weight | Approximately 3647 g/mol (with DAC linker) | 624.8 g/mol (free base); approximately 936.2 g/mol as the mesylate salt |
| Half-life | Substantially extended vs native GHRH; reported on the order of days (approximately 6-8 days) due to albumin binding via DAC | Approximately 24 hours (supports once-daily dosing in studies) |
| Origin | CJC-1295 (with DAC) is a synthetic long-acting GHRH analog based on a modified GHRH(1-29) sequence, developed by ConjuChem. It incorporates a Drug Affinity Complex (DAC) that binds serum albumin to greatly extend circulating half-life. | MK-677 (Ibutamoren, development code MK-0677) is an orally active, non-peptide growth-hormone secretagogue developed by Merck. It is a spiroindane/spiropiperidine small molecule, not a peptide. |
“Not documented” means the PeptiDex entry records no value for that field. Nothing on this page is estimated, and no figure is carried over from one compound to the other.
How CJC-1295 works
CJC-1295 is a GHRH-receptor agonist that stimulates pulsatile GH secretion from the pituitary. Its GHRH(1-29) backbone carries stabilizing amino-acid substitutions (e.g. at positions 2, 8, 15, 27) that resist DPP-4 degradation, and the DAC group forms a covalent bond with albumin, dramatically prolonging its action. This produces a sustained elevation of GH and IGF-1 rather than sharp discrete pulses.
How MK-677 (Ibutamoren) works
MK-677 is an agonist of the growth-hormone secretagogue receptor (GHS-R1a, the ghrelin receptor), mimicking ghrelin to stimulate pulsatile GH release from the pituitary and raise circulating IGF-1. Unlike the peptide GHRPs, it is orally bioavailable and long-acting. It can also modestly increase cortisol and appetite via ghrelin-receptor signaling.
Mechanistic descriptions reflect published research-literature understanding and are quoted from each compound's own entry. Much peptide research is preclinical (in-vitro or animal-model); mechanism in humans may differ and is not established for many compounds.
Where each one appears in the literature
The research contexts each entry documents. Listing a research area is not a claim of efficacy or a therapeutic indication, and the two lists are not scored against each other.
CJC-1295
MK-677 (Ibutamoren)
What sets each apart
CJC-1295
The DAC version's albumin binding gives it a far longer half-life (days) than the no-DAC 'Mod GRF 1-29' (minutes), making it the long-acting member of the CJC-1295 family.
MK-677 (Ibutamoren)
Unlike the peptide secretagogues in this class, MK-677 is a non-peptide, orally active, long-acting ghrelin-receptor agonist, making its route and pharmacokinetics fundamentally different.
Frequently asked questions
What is CJC-1295 (with DAC)?
CJC-1295 is a synthetic long-acting analog of GHRH(1-29). This slug refers to the DAC (Drug Affinity Complex) version, which carries a maleimidopropionic acid linker that covalently binds serum albumin after injection, dramatically extending its circulating half-life to several days.
What is the difference between CJC-1295 with DAC and without DAC?
Both share the same modified 29-amino-acid GHRH core with substitutions that resist DPP-IV cleavage. The DAC version adds an albumin-binding complex giving a half-life of roughly 6-8 days, producing a sustained 'GH bleed,' whereas the no-DAC version (Mod GRF 1-29) has only a ~30 minute half-life and produces discrete pulses.
What does the long half-life mean for research design?
Because CJC-1295 with DAC persists for days, it raises the baseline of GHRH tone rather than producing sharp pulses. In research this is described as elevating overall GH and IGF-1 output; studies often examine how this sustained tone interacts with pulsatile GHRP stimulation.
What is MK-677 (ibutamoren)?
MK-677 (ibutamoren) is an orally active, non-peptide growth hormone secretagogue that mimics ghrelin and binds the GHS-R1a receptor. Because it is a small molecule rather than a peptide, it survives digestion and is studied as an oral agent that raises GH and IGF-1 levels.
How does MK-677 differ from injectable GHRPs like ipamorelin?
MK-677 targets the same ghrelin receptor as injectable GHRPs but is a non-peptide small molecule with ~60-70% oral bioavailability, so it is taken by mouth rather than injected. Its long half-life sustains elevated IGF-1 across the day, unlike the discrete pulses from short-acting injectable GHRPs.
What does MK-677's long half-life imply for research?
MK-677 has a long biological half-life (reported ~24 hours of sustained IGF-1 elevation), which supports once-daily oral dosing in research protocols and produces a sustained elevation of GH/IGF-1 rather than a sharp pulse.
Answers are the ones published on each compound's own PeptiDex entry. They are educational summaries of research-literature context and are not medical advice.