CJC-1295 vs MK-677
Side-by-Side Comparison
| Attribute | Cjc 1295 | Mk 677 |
|---|---|---|
| Category | Growth Hormone Secretagogue | Growth Hormone Secretagogue |
| Mechanism | CJC-1295 binds to GHRH receptors (GHRHR) on pituitary somatotroph cells, activating intracellular cAMP signaling to stimulate both the transcription of the GH gene and pulsatile release of endogenous... | MK-677 binds to the ghrelin receptor (GHS-R1a) in the pituitary gland and hypothalamus, mimicking the hunger hormone ghrelin. |
| Evidence Rating | D — Preclinical | C — Phase I–II Clinical Trials |
| Clinical Status | Research-only / Not approved for human use | Multiple Phase II trials completed. Not FDA-approved. Investigational. |
| Safety Profile | Common: transient flushing/"head rush" within 5-10 minutes post-injection — hallmark of a potent injection, harmless and brief; Self-reported: flu-like symptoms, headaches, irritability, anxiety, nausea, hives (mild and transient) | Common: increased appetite (ghrelin agonism), water retention/mild edema, transient muscle pain; Metabolic: may elevate fasting blood glucose and reduce insulin sensitivity (dose-dependent); important for diabetics and pre-diabetics |
| Route | Subcutaneous | Oral (capsule or liquid) |
| Dose Range | No DAC: 100 mcg before bed daily; DAC: 1–2 mg 2–3x weekly | 10–25 mg/day orally |
| Frequency | Once daily (no DAC) or 2–3 times weekly (with DAC) | Once daily |
| Molecular Weight | No DAC: ~3367.9 g/mol; With DAC: ~3647.3 g/mol | ~528.7 g/mol (624.8 as mesylate salt) |
| Half-Life | No DAC (mod GRF 1-29): ~30 min; With DAC: ~8 days | ~4–6 hours (plasma); functional activity ~24 hours |
Overview
CJC-1295 and MK-677 are both research peptides studied across multiple applications. This comparison examines their mechanisms, evidence base, dosing protocols, and safety profiles to help researchers understand the key differences and overlaps.
CJC-1295 — Mechanism & Evidence
CJC-1295 is a synthetic analogue of growth hormone-releasing hormone (GHRH) originally developed by ConjuChem Technologies for HIV-associated lipodystrophy. It exists in two forms: with DAC (Drug Affinity Complex) for extended half-life of 5.8-8.1 days, and without DAC (Mod GRF 1-29) for shorter, pulsatile release with a half-life of approximately 30 minutes. Two 2006 randomized, placebo-controlled, double-blind clinical trials (Teichman et al.) demonstrated dose-dependent GH increases of 2-10 fold and IGF-1 increases of 1.5-3 fold in healthy adults aged 21-61. The No DAC version is generally considered the safer choice due to its physiological pulsatile pattern.
Key claims: Increases growth hormone and IGF-1; Improves body composition; Promotes deep sleep.
MK-677 — Mechanism & Evidence
MK-677 (Ibutamoren) is a potent, long-acting, orally-active, non-peptide ghrelin receptor (GHS-R1a) agonist that stimulates growth hormone release without injections. Unlike injectable GH peptides such as GHRP-6 or Ipamorelin, MK-677 can be taken orally and maintains elevated GH and IGF-1 levels for up to 24 hours. It has been studied in several human clinical trials for GH deficiency, muscle wasting, bone density, and sleep quality, but is not FDA-approved for any indication.
Key claims: Increases growth hormone and IGF-1 levels; Improves sleep quality; Increases lean body mass.
Shared Research Applications
Both peptides are studied for: Anti-Aging, Body Composition.
CJC-1295 is also researched for: no additional unique applications.
MK-677 is also researched for: Sleep.
Safety Considerations
CJC-1295: Common: transient flushing/"head rush" within 5-10 minutes post-injection — hallmark of a potent injection, harmless and brief Self-reported: flu-like symptoms, headaches, irritability, anxiety, nausea, hives (mild and transient) Water retention and edema (dose-dependent; elevated GH causes sodium/water retention via kidneys)
MK-677: Common: increased appetite (ghrelin agonism), water retention/mild edema, transient muscle pain Metabolic: may elevate fasting blood glucose and reduce insulin sensitivity (dose-dependent); important for diabetics and pre-diabetics Fatigue and lethargy reported by some users
Related Products
Related Research News
CJC-1295 with DAC and Ipamorelin: Growth Hormone Research Guide
CJC-1295 with DAC and Ipamorelin represent key compounds in growth hormone research, targeting distinct pathways for GH and IGF-1 signaling. CJC-1295 with DAC acts as a long-acting GHRH analogue with a half-life of 5.8 to 8.1 days, while Ipamorelin functions as a selective growth hormone secretagogue via the ghrelin receptor. Together, they support studies on metabolism, recovery, and body composition.
CJC-1295 + Ipamorelin: Growth Hormone Stack Mechanics
CJC-1295 and Ipamorelin form the most studied growth hormone peptide combination in research. They target separate receptor pathways to boost GH secretion through the somatotropic axis. This stack produces amplified GH pulses, with preclinical data showing 3 to 5 times baseline levels versus 1.5 to 2 times alone.
Ipamorelin: Selective GH Secretagogue for Clean Pulsatile Release
Ipamorelin, a third-generation GHS-R1a agonist (CAS 170851-70-4), stimulates pulsatile growth hormone release without elevating cortisol or prolactin, unlike earlier GHRPs. This selectivity supports precise research into GH axis effects, IGF-1 pathways, body composition, recovery, and sleep. Studies highlight its role in anabolic processes and synergy with CJC-1295 for enhanced GH output.