PepRank

MK-677

Also: ibutamoren · Nutrobal

SleepRecoveryOral

Oral GH secretagogue (not a peptide); hunger, bloat, insulin resistance, CHF signal.

Safety tier
Avoid
strict bar
Positive
48%
of 29 reports
Per month
≈ €18–54
estimate
Rank
#39
of 61 research peptides

At a glance

Access
Grey market
OralFelt in 15 min – 1 h, lasts 24 h
Strict case
GH/IGF-1 elevation, insulin resistance and a CHF safety signal in an RCT.
Best effects
Appetite and weight gain · deeper sleep · fuller muscles (water) · IGF-1 increase
Downsides
Intense hunger · water retention / bloat · lethargy · numb/tingling hands
Typical use
10-25 mg/day oral. Users report 9.6–23 mg/day (median 20 mg, n=7).
Stacked with
Stacked with
RAD-140 or other SARMs: The classic SARM-shop cycle; makes it impossible to tell what MK-677 itself did, and one documented RAD-140 + MK-677 cycle ended with ALT at three times normal. · Berberine or metformin: Taken by many users to blunt the rise in blood sugar; some also keep a glucometer. · Testosterone or AAS cycles: Used alongside gear for sleep, appetite and recovery. · Enclomiphene: Paired in 'natty plus' cycles to keep testosterone up while on SARMs.

Safety

Watch
Raises fasting glucose and HbA1c; insulin resistance · Congestive heart failure signal: hip-fracture RCT terminated early (FDA category 2) · GH/IGF-1 elevation
Tier by safety barStrict AvoidBalanced AvoidEvidence only Avoid
  • Seen harm2 of 3
  • Mechanism2 of 3
  • Data gap1 of 3
  • Silent harm3 of 3
  • Product2 of 3
Never if
Active cancer or a history of cancer · Heart failure or significant heart disease · Diabetes or impaired glucose tolerance · Pregnancy or breastfeeding (no human reproductive data)
Why each score
Seen harm 2/3
A randomised trial in 123 older hip-fracture patients was stopped early for a congestive heart failure signal, which FDA cites as its reason for barring it from compounding. Adunsky et al. 2011: MK-677 in hip-fracture recovery, stopped for a heart-failure signal (PubMed 21067829) ↗FDA: bulk drug substances that may present significant safety risks (category 2 and withdrawn nominations) ↗
Mechanism 2/3
An oral ghrelin mimetic that raises IGF-1 by 50-70% for as long as it is taken; over two years it raised fasting glucose, cut insulin sensitivity and raised cortisol, with oedema. Nass et al. 2008: two-year MK-677 trial in older adults, glucose up and insulin sensitivity down (Ann Intern Med, PubMed 18981485) ↗Sevigny et al. 2008: MK-677 for 12 months in 563 Alzheimer patients (Neurology, PubMed 19015485) ↗
Data gap 1/3
Never approved, but tested in sizeable RCTs: 563 Alzheimer patients for a year and 65 older adults for two years. Sevigny et al. 2008: MK-677 for 12 months in 563 Alzheimer patients (Neurology, PubMed 19015485) ↗Nass et al. 2008: two-year MK-677 trial in older adults, glucose up and insulin sensitivity down (Ann Intern Med, PubMed 18981485) ↗
Silent harm 3/3
IGF-1-driven tumour promotion would be silent and delayed; the glucose rise shows on a blood test and fluid retention is visible. Nass et al. 2008: two-year MK-677 trial in older adults, glucose up and insulin sensitivity down (Ann Intern Med, PubMed 18981485) ↗
Product 2/3
Sold as grey-market oral research-chemical liquid or capsules.

User reports

All 29 reports →
Users report
Lifters like the appetite, sleep and fullness, but most say gains are mostly water and fat. People keep glucometers or berberine handy because of insulin resistance. Lethargy, tingling hands and bloat are routine. 'Just run HGH' is a common verdict.
Glowing 3Positive 11Mixed 4Nothing 2Negative 6Bad reaction 3
  • r/NooTopics· · 47 upvotesOriginal ↗

    The mk has flipped my life on its head. I used to sleep 12+ hours, now I feel perfect off of 6.5, sleep study scores have tripled

    GlowingEnergy · 2.5 mg/day · Oral · ~3 months

    severe chronic fatigue for 5 years

  • r/suppgains· · 37 upvotesOriginal ↗

    MK677 solved a lot of long standing seemingly unrelated issues I had that no Dr had worked out, in the space of about a week.

    GlowingRecovery · Oral

    competitive bodybuilder also using AAS

  • r/moreplatesmoredates· · 62 upvotesOriginal ↗

    Second pic 🤬5 month ibutamoren. Feel like my arms shrunk lol? Might just be excessive water distorting the perception but not convinced. Can see overall way more water weight.

    NothingMetabolic · Oral · 5 months

Where to buy

All 5 offers →
Getting it
Never approved anywhere; sold as capsules or liquid by SARM and research-chemical shops, often mislabelled or swapped (MK-777 products have tested as LGD-4033). FDA category 2 bars compounding; banned by WADA.

No listing can be priced, so the researchers estimate ≈ €18–54 a month.

No trusted shop in the EU lists it; every listing is on the buy page.

Studies

Evidence
Human RCTs — Elderly, hip fracture, obesity; not approved
3 more studies and 2 sources

Sources

Molecule

Modifications
not a peptide: ibutamoren, small-molecule ghrelin receptor agonist

Sequence

The peptide's chain of amino acids from its start (the N-terminus) to its end, one bead and one letter for each: A alanine, C cysteine, D aspartic acid, E glutamic acid, F phenylalanine, G glycine, H histidine, I isoleucine, K lysine, L leucine, M methionine, N asparagine, P proline, Q glutamine, R arginine, S serine, T threonine, V valine, W tryptophan, Y tyrosine. A modification such as an N-acetyl cap or a C-terminal amide changes how long it lasts in the body. Length tells related peptides apart, from a two-residue dipeptide like carnosine to a 43-residue protein like thymosin beta-4, and predicts neither effect nor safety.

Report grades

Every first-hand Reddit or X report is graded on its own, from glowing through positive, mixed, nothing and negative to bad reaction, and the bar shows how those grades split. Posts that look vendor-adjacent stay on the peptide's page but are left out of the counts.

GlowingPositiveMixedNothingNegativeBad reaction

% positive

The share of a peptide's graded Reddit and X reports that are glowing or positive, vendor-adjacent posts left out. A peptide with few reports is pulled toward the average of all reports, as if it had eight average ones besides its own, so two glowing posts cannot top the list. Peptides rank by this figure, those with no graded report yet after those with one, and Avoid ones after every other entry.

Researcher estimate

No first-hand report of this peptide has been graded yet, so the figure is the researchers' own rating out of 10 from what they read about it. It ranks after every peptide with graded reports until its own arrive.

Safety tier

Each peptide is tiered Clean, Caution or Avoid from its five risk axes under the chosen safety bar. An Avoid peptide carries a real risk of harm, a plausible route to serious harm rather than mere unpleasantness, so it stays listed with the reason but ranks behind every other entry, however good its reviews.

Safety bar

The safety bar sets how much risk it takes to rate a peptide Avoid. Strict: out on any serious mechanism with little human data, or any documented serious harm. Balanced: out on documented serious harm (unless it is obvious, reversible and from a regulated product), or a serious mechanism whose harm would be silent with no human data at all. Evidence only: out only on documented serious harm in humans that is lasting, delayed or from grey-market product.

Seen harm

Documented serious adverse events in humans, from 0 for none despite real exposure to 3 for deaths or several well-documented serious harms. Serious means a hospital or emergency visit or harm lasting weeks, so a headache or a bad night does not count.

Mechanism

A plausible biological route to serious harm at the doses people use, such as growth-factor signalling, hormone-axis suppression, heart or blood-pressure effects or immune activation. It runs from 0 when none is known to 3 when a dangerous pathway has been shown in living animals.

Data gap

How little human safety data exists for the molecule actually sold, from 0 for an approved drug with large trials and years of use to 3 for no human safety data at all. A modified analogue does not inherit its parent's trials.

Silent harm

Whether the feared harm would show quickly or stay hidden, from 0 when it is obvious and goes on stopping to 3 when it is silent and delayed, like tumour promotion or slow organ damage. User reports cannot reveal a harm that takes years to appear, so a high score here limits what good reviews can tell you.

Product

The risk of what people actually buy, from 0 for a regulated pharmacy or supplement product taken by mouth or on the skin to 3 for a grey-market injectable. In one dataset of 6,441 grey-market samples, 42–71% failed basic quality criteria and 15% carried endotoxin; taken by mouth or in the nose, a pack avoids the injection risks.

Evidence

The strongest kind of study behind the peptide's effects, from an approved drug through human controlled trials and small human studies to animal work or nothing of its own. Animal results often fail to carry over to people.

Access

How people get it: as an approved drug, a compounded prescription, an over-the-counter supplement or from the grey market, where nobody checks the vial. The channel decides both the legal position and the risk of a bad batch.

Price per month

Thirty days of the typical dose, from its low end to its high end, priced at the listing a careful buyer would choose: in stock, from a shop scoring 4 of 5 on trust (third-party tested where no score is set), failing that 3, a pure pack before a blend, a European shop first, then the cheapest per mg. The range is the dose's, not the shops'. A per-dose amount counts once a day unless the dose says otherwise. Prices are in euros at ECB rates of 2026-10-29, before shipping; the shop table keeps each listing's price per mg, per gram for bulk supplements. Where no listing can be priced the researchers' own estimate stands in, and says so.

Dose users report

The middle half of the daily doses stated in at least five first-hand reports, vendor posts left out. Where its middle sits more than twice above or below the declared dose, the month is priced at it as well, since what people take is what they pay for.

Shop trust

Each shop's trust on a 1–5 scale, read from its testing and its reputation: 1 for serious red flags (fabricated COAs, scam reports, impersonation, a closed shop), 2 for no public testing, a new shop or active complaints such as seized parcels, 3 for its own COAs or a short track record, 4 for verified third-party testing or a strong reputation, and 5 for third-party batch reports that name the shop, with years of good independent reputation. A shop without a score counts third-party batch testing as 4, its own COAs as 3 and no public tests as 2.

Best value

Within a category or a goal, a peptide that no other beats on both counts: none is rated more positively for the same or a lower monthly price, and none costs less for the same or a higher rating. The chart joins these into the best-value line; the cheapest of them and the best-rated of them both make it, so the line spans the trade-off from cheap to best. Avoid entries never count, and a peptide needs both a % positive and a price to be compared.

Testing

Whether the shop publishes lab results: third-party tested means an independent lab checks each batch, own COA means the shop's own certificate of analysis, and no public tests means neither. A certificate shows purity, not safety.

Added peptide

Some packs sold under one peptide's name hold a second one, such as 5 mg GHK-Cu in a nasal kit, stated only in the description. Sprayed in the nose or injected it reaches the blood like an injection, so it carries the risk of that route and is tiered as the injectable form, whatever its tier on the skin. A pack whose page gives no contents list may hold more than its name.