Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of CJC-1295 and MK-677 — mechanism, side effects, legal status, and pricing.
CJC-1295 is a synthetic tetrasubstituted analog of growth hormone-releasing hormone (GHRH 1-29) originally developed by ConjuChem. The name historically refers to the DAC-modified (Drug Affinity Complex) form that covalently binds serum albumin, producing a 6–8 day half-life; a separate no-DAC form (also called Modified GRF 1-29) shares the same tetrasubstituted backbone but lacks the albumin-linking maleimidopropionyl-lysine and has a half-life of roughly 30 minutes. Not FDA-approved in any form; ConjuChem halted Phase 2 development around 2007 after a patient death in an HIV-lipodystrophy trial (ultimately judged by investigators to be unrelated to the drug, but development was terminated regardless).
MK-677 (ibutamoren, MK-0677, L-163,191) is an orally active, non-peptide small-molecule growth hormone secretagogue developed by Merck in the 1990s. It is a spiropiperidine ghrelin-receptor (GHSR-1a) agonist — not a peptide and not a SARM, though it is commonly misclassified as both in grey-market retail. Merck discontinued development after mixed efficacy and adverse metabolic / cardiovascular findings; it is not FDA-approved.
CJC-1295
MK-677
Category
Legal Status
Mechanism
Half-life
Side Effects
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CJC-1295
MK-677
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CJC-1295
115
COAs
98.8%
Avg purity
12
Labs
MK-677
5
COAs
98.3%
Avg purity
3
Labs
CJC-1295 is among peptides under FDA review for the Category 1 (503A) list; if added, it would require a prescription to be compounded by registered 503A/503B pharmacies — not yet authorized. MK-677 remains research-only. In April 2026 the FDA removed 12 peptides from Category 2, which does not place them on the Category 1 list or authorize compounding. The FDA's Pharmacy Compounding Advisory Committee is advisory and meets July 23–24, 2026 to review nominations and make recommendations to the FDA.
In healthy adults, single SubQ doses of CJC-1295 (with DAC) elevated plasma GH 2- to 10-fold for ≥6 days and IGF-1 1.5- to 3-fold for 9–11 days (Teichman et al., JCEM 2006), and pulsatile GH secretion was preserved rather than suppressed during continuous stimulation (Ionescu & Frohman, JCEM 2006). Despite these Phase 1/2 findings, ConjuChem halted Phase 2 lipodystrophy development in 2006–2007 after a trial participant died of a myocardial infarction; the event was deemed most likely due to pre-existing coronary disease, but the program was not resumed. No CJC-1295 form is FDA-approved for any indication. Grey-market use almost always refers to the no-DAC / Modified GRF 1-29 form, often stacked with ipamorelin; neither variant is clinically validated for anti-aging, body composition, or performance indications.
Key references
MK-677 has meaningful human data from Merck-sponsored Phase I/II trials. Murphy et al. (JCEM 1998, PMID 9467534) showed 25 mg MK-677 reversed nitrogen wasting during caloric restriction in healthy adults. Svensson et al. (JCEM 1998, PMID 9467542) reported ~40% IGF-1 elevation, increased fat-free mass, and higher energy expenditure over 8 weeks in obese men. Copinschi et al. (Neuroendocrinology 1997, PMID 9349662) documented improved slow-wave and REM sleep in young and older adults. Nass et al. (Ann Intern Med 2008, PMID 18981485) — the pivotal 2-year randomized trial in 65 healthy older adults — restored GH and IGF-1 to young-adult levels and increased fat-free mass, but produced modest fasting glucose elevation and insulin resistance. The Adunsky et al. Phase IIb hip-fracture trial (Arch Gerontol Geriatr 2011, PMID 21067829) was stopped early after a congestive-heart-failure safety signal (4/62 ibutamoren vs 1/60 placebo). Merck discontinued development. MK-677 is commonly mislabeled as a 'SARM' in grey-market retail — it is not; it is a ghrelin-receptor agonist and oral GH secretagogue. It has never been FDA-approved.
CJC-1295 and MK-677 are both in the Performance category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Contraindications
Lab Testing
Key references