BPC-157 + MK-677 + GHRP-2
The number went up 84%. Nothing else moved.
MK-677 nearly doubled IGF-1 in 161 elderly patients recovering from hip fractures, and improved none of the four measures of how well they could move. IGF-1 is the hormone growth hormone produces downstream, and the blood marker people track to check whether a growth hormone compound is doing anything. A second trial in the same population was stopped early for heart failure. This stack pairs it with a second compound hitting the same receptor.
MK-677 is not a peptide, and it is the most tested thing here.
MK-677 is an oral small molecule. It is not a peptide at all.[1] It sits in peptide stacks because it hits the same receptor as the injected ones and comes as a pill, which is the main reason people choose it.
It also has a full clinical trial record, because Merck ran one. That makes it unusual here, and the record is the reason Merck stopped. Merck discontinued development after the functional endpoints failed repeatedly and a heart failure signal appeared in the elderly.[1]
A biomarker that rises, and outcomes that do not follow it.
Everyone in these trials was split by chance between the real compound and a placebo, a dummy treatment with nothing active in it, and neither patients nor doctors knew who got which. Hip fracture recovery in elderly patients was the most plausible use anyone could think of, since those are people who have lost muscle, need to rebuild it, and can be measured walking. It was tested twice, in two separate trials.
Patients on MK-677 did numerically better on three of the four lower-limb measures. None of those differences reached significance against placebo, and the overall sickness-impact score showed nothing either.[1][4]
This gap is the whole point. IGF-1 is the number people measure to decide whether a growth hormone compound is working, and here it nearly doubled while nothing a patient would notice changed. A biomarker moving shows the compound is doing something. Whether that something is useful takes a different measurement.
A two-year trial by Nass found fat-free mass rose by 1.1 kg against placebo.[1] That is a real measured effect on body composition, and it is the strongest positive finding in the MK-677 literature. It is also about a kilogram over two years, alongside the metabolic changes below.
Six and a half percent against one point seven.
Adunsky and colleagues ran a second hip fracture trial in 2011, 123 patients aged 60 and over, planned for 24 weeks. It did not finish. Congestive heart failure occurred in 6.5% of the MK-677 group against 1.7% on placebo, and the trial was halted on that imbalance.[2]
The investigators concluded the safety profile was unfavourable in that population, and Merck did not take the compound further.
Read the qualifier in both directions. Those were frail elderly people recovering from a hip fracture, many with existing cardiac vulnerability, and the risk does not transfer straight to a healthy adult in their thirties. The likely mechanism is fluid retention in people whose hearts were already struggling.[3]
It is also the only trial that ran MK-677 in a frail group and looked hard at cardiac outcomes, and it was stopped. Nobody has run the equivalent trial in healthy adults, so there is no dataset saying the signal does not apply to them either.[4]
Most of these were counted against a control group.
Because Merck ran controlled trials, the rates below come with a comparison group. Almost nothing else in this catalogue has one.
| Effect | On MK-677 | On placebo | Notes |
|---|---|---|---|
| Increased appetite | 67% | 36% | Direct result of hitting the ghrelin receptor, the hunger switch |
| Mild lower-limb swelling | 44% | 27% | Growth hormone causes the body to hold sodium and water |
| Muscle pain | 33% | 9% | Transient |
| Congestive heart failure | 6.5% | 1.7% | Frail elderly population. Trial terminated on this finding |
| Fasting glucose | rose | not reported | Every trial that measured it found an increase. Insulin sensitivity fell |
| Prolactin | +23% | not reported | Measured by Chapman |
The glucose finding is replicated across trials, and it is the one that matters most for who should avoid this.[4] Nass documented an average rise in fasting glucose with significantly reduced insulin sensitivity over twelve months.[5] Anyone with diabetes, pre-diabetes or existing insulin resistance is looking at a compound that reliably makes that worse.
MK-677 also antagonises the effect of insulin and oral glucose-lowering drugs through the same route.[3]
Two of the three compounds open the same door.
Growth hormone compounds reach the pituitary through one of two switches. The standard argument for stacking them is to take one from each.
Both act here. MK-677 is oral and lasts around a day, giving continuous exposure. GHRP-2 is injected and clears in a couple of hours, giving a pulse. Different timing, same switch.
The other door stays shut. Opening it takes a GHRH analog such as CJC-1295 or sermorelin, and this stack contains neither of them.
So this is three purchases, one growth hormone mechanism and one repair compound. The version of this stack that follows its own logic would swap GHRP-2 for a GHRH analog, or drop one of the two and keep the money.
The timing difference is a real argument and an untested one, since nobody has studied whether continuous exposure alongside a pulse produces anything a single compound would not.
BPC-157 is the part with no overlap. It is aimed at tissue repair instead of growth hormone, which makes it the one compound here doing a separate job from the other two. Its own evidence is animal-only, and it reached a Phase 2 trial in ulcerative colitis whose results were never published.
An advisory committee looked at it and said no.
MK-677 is not approved in any country for any indication.[2] In 2024 the FDA's Pharmacy Compounding Advisory Committee reviewed it for the 503A Bulks List and voted against, citing fluid retention, heart failure risk and raised blood sugar.[2] The 503A list is the register of substances compounding pharmacies are allowed to make medicines from.
It is not eligible for compounding under 503A or 503B.[1] An Australian government-funded men's health body answers the question of whether it is worth taking in two sentences: no, because there is no evidence of benefit and plenty of harmful side effects.[5]
That is a blunter verdict than we would write ourselves, and it comes from a public health body with nothing to sell and no commercial interest in the answer.
What people ask about this stack
Does MK-677 build muscle?
A two-year trial found fat-free mass rose by 1.1 kg against placebo, which is a real measured effect and the strongest positive finding in its literature. Two separate hip fracture trials found it raised IGF-1 by 84% and improved no measure of function. So it changes body composition slightly, and the trials that looked for a difference in what people could do found none.
Why was an MK-677 trial stopped early?
Congestive heart failure occurred in 6.5% of the MK-677 group against 1.7% on placebo in a 2011 hip fracture trial of 123 patients aged 60 and over. The trial was halted and the investigators concluded the safety profile was unfavourable in that population. Those patients were frail and often had existing cardiac problems, so the figure does not transfer directly to a healthy adult. It is also the only trial that looked hard at cardiac outcomes, and no equivalent has been run in healthy people.
Who should avoid MK-677?
Anyone with diabetes, pre-diabetes or existing insulin resistance. Rising fasting glucose and falling insulin sensitivity showed up in every trial that measured them. MK-677 also works against insulin and oral glucose-lowering drugs through the same route. Anyone with heart problems has the trial above to consider. This is information. The decision is a conversation for a doctor.
Is MK-677 a peptide?
No. It is an oral small molecule that acts on the ghrelin receptor, the same target as the injected growth hormone releasing peptides. It appears in peptide stacks because of what it does to the same receptor the injected ones hit.
Do MK-677 and GHRP-2 do different things?
They act on the same receptor. MK-677 is oral and lasts about a day. GHRP-2 is injected and clears in about two hours. The timing differs and the target does not, so running both is one mechanism bought twice. Whether continuous exposure plus a pulse beats either alone has never been studied. Compare against the other stacks.
Is MK-677 legal?
It is not approved in any country for any indication. An FDA advisory committee reviewed it in 2024 for the compounding list and voted against, citing fluid retention, heart failure risk and raised blood sugar. It cannot be compounded under 503A or 503B. It is also banned in sport by the World Anti-Doping Agency.
Every reference carries how it was read.
MK-677 has registered trials with PubMed identifiers, so most claims here trace to named studies. The trial figures themselves were read through secondary summaries.
- 01Bach et al. 2004, Journal of the American Geriatrics Society, PMID 15066065. 161 patients aged 65+ across 13 sites, six months, double-blind placebo-controlled. IGF-1 +84% against +17%, no functional measure significant. Also the source for the Nass two-year 1.1 kg fat-free mass finding, Merck's discontinuation, and 503A and 503B ineligibility.
- 02Adunsky et al. 2011, PMID 21067829. Phase 2b, 123 patients aged 60+, terminated early. CHF 6.5% against 1.7%. Also the source for the 2024 PCAC vote against the 503A Bulks List.
- 03Side effect and interaction profile: fluid retention mechanism, cardiac vulnerability in the elderly, antagonism of insulin and oral glucose-lowering drugs.
- 04Trial summary including the Chapman prolactin figure and the assessment that glucose and insulin effects are replicated across trials.
- 05Adverse event rates against placebo in adults aged 60+, the Nass twelve-month glucose and insulin sensitivity findings, and the Healthymale assessment quoted.
- 06Peptide Decoding vendor pricing data, 12 September 2026. Single-compound listings only.