MK-677 is an oral, small-molecule drug developed by Merck that mimics ghrelin to raise growth hormone and IGF-1. It is not actually a peptide, but sits on the same GH-axis "stack." Multiple phase 2 trials ran for frailty and hip-fracture recovery; all were halted, partly over insulin-resistance signals. It is banned at all times by WADA.
CJC-1295 is a synthetic copy of growth hormone–releasing hormone (GHRH), engineered to last in the body for days rather than minutes. It was tested in early human trials in the mid-2000s, abandoned by its developer, and now circulates only as a research chemical. It is not an approved medicine anywhere, and is banned at all times in tested sport by WADA.
MK-677 sits at grade C; CJC-1295 at grade D. On evidence alone, MK-677 is the safer recommendation. That said, "stronger evidence" doesn't always mean "right for you", read both pages, then talk to a clinician.
Murphy et al. 1998 showed MK-677 reversed protein catabolism in healthy volunteers on a calorie-restricted diet. Several phase 2 programmes followed in GH-deficient adults; none progressed to approval.
The Teichman 2006 Phase I trial established that a single dose raises GH and IGF-1 for several days. This is a pharmacokinetic finding, not a clinical outcome, no approved indication followed.
ConjuChem ran a Phase II trial for fat-redistribution in HIV-positive patients. The trial was halted in 2006 after a patient death; development of CJC-1295 was effectively abandoned soon after.
Widely used off-label in bodybuilding circles, often stacked with ipamorelin or other GH secretagogues. No controlled human trial has tested body-composition endpoints.
The most important real-world finding from the human trials is impaired insulin sensitivity: fasting glucose and HbA1c rose meaningfully in healthy older adults on chronic dosing (Nass et al. 2008), and the effect was large enough that it would push some users into a pre-diabetic range. This is not a vendor scare-story, it is a phase 2 trial result. Other consistently reported effects include water retention, increased appetite, transient muscle aches and mild lethargy. In the frail elderly, the Adunsky hip-fracture trial reported serious adverse events including congestive heart failure signals, part of why that programme was halted. Long-term tumour risk via sustained IGF-1 elevation is a theoretical concern (IGF-1 is mitogenic) and a reason for caution in anyone with active cancer or a cancer history. Products sold as "MK-677" or "Nutrobal" outside the trials are unregulated; purity, dose accuracy and contamination are real risks.
The safety profile in humans is essentially unknown. The Teichman Phase I trial reported headache, flushing, and injection-site reactions as the commonest dose-related adverse events. The class as a whole, GH secretagogues, is associated with reduced insulin sensitivity, raised blood glucose, and fluid retention at doses that meaningfully raise IGF-1, all of which are concerns for long-term, unsupervised use. There is also a well-recognised theoretical risk that sustained IGF-1 elevation could promote the growth of existing tumours; this has not been demonstrated for CJC-1295 specifically but is a standard caution across the GH/IGF-1 axis.
A single trial-participant death occurred during the 2006 ConjuChem lipodystrophy Phase II study; the attending physician's judgement was that the death (asymptomatic coronary disease with plaque rupture) was most likely unrelated to CJC-1295, but the study was halted and the programme was effectively abandoned shortly after. Online lore that has grown around this, including reports of unexplained deaths in users in subsequent years, is poorly documented and causation has not been established. We mention it because it is part of the public record, not because the link is proven.
MK-677 sits at grade C; CJC-1295 at grade D. On evidence alone, MK-677 is the safer recommendation. That said, "stronger evidence" doesn't always mean "right for you", read both pages, then talk to a clinician.
Pepwyse comparison pages are generated from the same structured data behind each peptide profile. Want a different head-to-head? Use the compare picker or ask MK-677 directly via the Ask-Peppy button. Not medical advice, see how we grade evidence.