The TL;DR.
MK-677 (Ibutamoren) is a potent, orally active growth hormone secretagogue. By binding to the ghrelin receptor (GHSR-1a) in the pituitary gland and hypothalamus, it stimulates a sustained release of endogenous growth hormone and insulin-like growth factor 1 well-established.[1]
Unlike injectable peptides like Ipamorelin or CJC-1295, MK-677 is taken orally and has a long half-life of approximately 24 hours, allowing for once-daily dosing.[8] It is highly effective at raising IGF-1 levels, but it comes with significant side effects — most notably a massive increase in appetite, water retention, and a reduction in insulin sensitivity well-established.[2]
How it's actually used.
Before you start
- Identify the goal. MK-677 is primarily used for bulking due to its intense appetite-stimulating effects.
- Understand the regulatory status. MK-677 cannot be legally prescribed or compounded in the US. Sourcing requires the unregulated research-chemical market.
- Check your sport's rules. MK-677 is prohibited by WADA and most major sporting organizations.
- Baseline bloodwork. Do not start MK-677 without knowing your baseline fasting blood glucose and HbA1c.
Standard community dosing
Doses above 25 mg do not significantly increase GH/IGF-1 further but do increase side effects (diminishing returns). community
Reconstitution math
N/A — MK-677 is an oral compound (liquid suspension or capsule). No reconstitution is required.
Dosing timing
Timing depends entirely on the user's goal regarding the appetite side effect:
- To avoid hunger: take the dose immediately before bed. This allows the user to sleep through the most intense ghrelin spike. community
- To utilize hunger (bulking): take the dose first thing in the morning to stimulate appetite throughout the day. community
Missed doses
- Missed 1 day: take the normal dose the next day. Do not double-dose.
- Missed 3+ days: resume the normal protocol.
Community consensus and real-world experience
In community discussions, MK-677 is highly regarded as a bulking tool because it forces a caloric surplus via intense hunger. Users report rapid initial weight gain (5–10 lbs in the first two weeks), almost entirely due to water retention and increased glycogen storage. community[11] The lethargy side effect is frequently discussed, with many users switching to nighttime dosing to mitigate daytime tiredness. community[14]
Log daily glucose, dose, and weight on one timeline.
MK-677 only works if you can catch insulin-resistance creep before it becomes permanent. Track every morning glucose reading next to your dose, weight, and HbA1c trend.
What to eat alongside.
Because MK-677 reliably decreases insulin sensitivity and raises fasting blood glucose, nutritional support is mandatory.
Macronutrient adjustments
- Carbohydrates — monitor carbohydrate intake to avoid exacerbating insulin resistance. High-glycemic diets on MK-677 rapidly degrade metabolic health.
Micronutrient adjustments
No data available — MK-677 does not have specific micronutrient dependencies.
Synergistic supplements
- P-5-P (Vitamin B6) — 100–300 mg daily. MK-677 can mildly elevate prolactin; P-5-P is often used to keep prolactin in range. community
Protective supplements
- Berberine — 500 mg taken 2–3× daily with carbohydrate-containing meals. Acts as a glucose disposal agent to help manage blood sugar. community
What can go wrong.
Reported side effects
Drug interactions
No formally documented drug interactions. Caution is advised when combining with medications that affect blood glucose (e.g., metformin, insulin) — the additive effect on insulin axis is unknown.
Contraindications
- Pre-existing diabetes or pre-diabetes — MK-677 will worsen glycemic control
- Active malignancy — sustained IGF-1 elevation provides a pro-growth environment
- History of severe edema or congestive heart failure (water retention)
Red flags
- Fasting blood glucose consistently reads above 100 mg/dL (5.5 mmol/L)
- Severe, pitting edema (swelling) in the lower extremities
Pregnancy, lactation & fertility
No data available — MK-677 has not been studied in pregnant or lactating women, nor has its effect on human fertility been evaluated. It should be strictly avoided in these populations.
Theoretical risks
- Pancreatic beta-cell exhaustion. Long-term, sustained stress on the insulin axis could theoretically lead to permanent beta-cell dysfunction (Type 2 diabetes) in susceptible individuals.
What to combine it with.
MK-677 + LGD-4033 or RAD-140
A common — though high-risk — bodybuilding stack. The SARM drives muscle protein synthesis; MK-677 drives appetite, allowing the user to eat in a massive caloric surplus. Both compounds negatively impact health markers. community[11]
MK-677 + CJC-1295 (with DAC)
Combines the oral ghrelin mimetic with a long-acting GHRH mimetic to hit both pathways simultaneously for sustained GH/IGF-1 elevation. community[13]
Anti-pattern stacks — avoid
- MK-677 + Ipamorelin / GHRPs. Both compete for the same GHSR-1a receptor. Stacking them provides no additional benefit and increases the risk of receptor desensitization.
- MK-677 + high-carb diet. Rapidly accelerates the onset of severe insulin resistance.
How to train on it.
MK-677 is primarily used during hypercaloric (bulking) phases. Its effects are gradual and depend heavily on diet and training adherence.
Expected trajectory
Training adjustments
- Expect a pump. The increased intracellular water and glycogen often lead to intense, sometimes painful muscle pumps during training.
Cut / recomp / bulk contexts
- Cut: Poor choice. The intense appetite stimulation makes adhering to a caloric deficit extremely difficult, and water retention masks fat loss.
- Recomp: Acceptable at low doses (10 mg) if appetite can be controlled.
- Bulk: Excellent. Ghrelin mimicry is highly effective at forcing a caloric surplus for individuals who struggle to eat enough.
How to store it.
Store at room temperature, away from direct sunlight. Do not refrigerate — the compound may crash out of solution.
Store in a cool, dry place. BUD typically 2 years from manufacture.
Light & freeze sensitivity
- Light — keep away from direct sunlight.
- Freeze — do not freeze liquid suspensions.
Sourcing & legal access
- United States. Investigational new drug. Not approved for human use.
- Cost-per-cycle (USD). Typically $40–$80 per month via research-chemical vendors.
- Global. Not approved as a human therapeutic in any major jurisdiction.
What to track.
Daily home glucose monitoring is required for this compound. A standard over-the-counter glucometer is sufficient. Check every morning, fasted.
Baseline panel
Mid-cycle panel
Post-cycle panel
Doctor handoff
vs. similar compounds.
| MK-677 | Ipamorelin | CJC-1295 (No DAC) | Exogenous HGH | |
|---|---|---|---|---|
| Class | Oral GHSR agonist | GHRP (ghrelin mimetic) | GHRH mimetic | Bio-identical hormone |
| Route | Oral | SC | SC | SC |
| Appetite | Extreme | None | None | None |
| Insulin impact | High risk | Low risk | Low risk | High risk |
| Half-life | ~24 hours | ~2 hours | ~30 min | ~10–20 min |
When to pick MK-677
Choose MK-677 only if oral administration is mandatory or if extreme appetite stimulation is desired for bulking.
When to pick Ipamorelin
Choose Ipamorelin for a clean, side-effect-free GH pulse — especially for anti-aging and sleep improvement.
When to pick CJC-1295
Choose CJC-1295 to stack with Ipamorelin to amplify the pulse via the GHRH pathway.
When to pick exogenous HGH
Choose HGH for exact bio-identical replacement — typically prescribed by a physician for diagnosed deficiency.
What the mechanism looks like.
Mechanism of action
MK-677 (Ibutamoren mesylate) is a non-peptide spiropiperidine that acts as a potent, orally active, selective agonist of the GHSR-1a. By mimicking ghrelin, it stimulates the pituitary gland to release GH. Crucially, it amplifies the natural pulsatile release of GH rather than causing a continuous, unnatural elevation.[6]
Pharmacokinetics
MK-677 has excellent oral bioavailability (over 60%). Following a single oral dose, it produces a sustained increase in GH and IGF-1 levels. The terminal half-life is approximately 24 hours, which supports once-daily dosing.[8]
Active metabolites
No data available — specific active metabolites in humans are not fully characterized.
Human clinical trials
Unlike many peptides in this category, MK-677 has a robust human clinical trial history — including a 2-year randomized controlled trial in older adults.
| Study | n | Duration | Population | Result |
|---|---|---|---|---|
| Copinschi (1996) | Small | 7 days | Healthy young men | ↑ GH pulsatility & IGF-1; transient cortisol/prolactin rise |
| Chapman (1996) | Small | 14 days | Healthy elderly | Restored GH/IGF-1 to young-adult levels |
| Smith (1997) | Small | Single dose | Healthy volunteers | Established 24-h half-life |
| Murphy (1998) | 8 | 14 days | Diet-restricted volunteers | Reversed diet-induced nitrogen wasting |
| Svensson (1998) | 24 | 8 weeks | Obese young males | Increased bone turnover markers |
| Nass (2008) | 65 | 2 years | Healthy older adults | ↑ IGF-1 & fat-free mass; ↑ fasting glucose |
| Sevigny (2008) | 416 | 12 months | Alzheimer's patients | Raised IGF-1; did not slow disease |
| Adunsky (2011) | 123 | 6 months | Hip-fracture patients | ↑ IGF-1 & lean mass; no functional benefit |
Open questions
- Does long-term pancreatic beta-cell stress from sustained MK-677 use lead to permanent insulin resistance in young, healthy athletic populations? (No longitudinal data exists.)
Frequently asked.
Is MK-677 a SARM?
No. It is often sold alongside SARMs, but it is a growth hormone secretagogue. It does not affect testosterone levels.
Will MK-677 make me fail a drug test?
Yes. It is banned by WADA and will cause a failure on any test looking for performance-enhancing drugs.
Why am I so tired on MK-677?
Lethargy is a very common side effect, likely related to the sustained elevation of IGF-1 and alterations in blood glucose dynamics. Taking the dose at night can help mitigate daytime lethargy.
Do I need to cycle off MK-677?
While it doesn't desensitize the GH receptor quickly, users must cycle off if their fasting blood glucose begins to climb. Many users run it for 3–6 months.
Does MK-677 cause water retention?
Yes — significant water retention is almost universal, often resulting in a puffy face ("moon face") and sudden weight gain on the scale.
Where it stands, by jurisdiction.
Last verified · May 17, 2026
Is MK-677 for you?
What we cited.
- Murphy M.G. et al. (1998). MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism. J Clin Endocrinol Metab. 83(2):320–325. PMID: 9467533.
- Nass R. et al. (2008). Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults. Ann Intern Med. 149(9):601–611. PMID: 18981485.
- Sevigny J.J. et al. (2008). Growth hormone secretagogue MK-677: no clinical effect on AD progression. Neurology. 71(21):1702–1708. PMID: 19015485.
- Adunsky A. et al. (2011). MK-0677 for hip-fracture recovery: a phase-IIb study. Arch Gerontol Geriatr. 53(2):183–189. PMID: 21035201.
- Svensson J. et al. (1998). MK-677 increases markers of bone formation and resorption in obese young males. J Bone Miner Res. 13(7):1158–1166. PMID: 9661080.
- Copinschi G. et al. (1996). Effects of a 7-day treatment with MK-677 on 24-hour GH profiles. J Clin Endocrinol Metab. 81(8):2776–2782. PMID: 8768828.
- Chapman I.M. et al. (1996). Stimulation of the GH–IGF-1 axis by daily oral MK-677 in healthy elderly subjects. J Clin Endocrinol Metab. 81(12):4249–4257. PMID: 8954023.
- Smith R.G. et al. (1997). Peptidomimetic regulation of growth hormone secretion. Endocr Rev. 18(5):621–645. PMID: 9331546.
- Reddit r/sarmsourcetalk. "MK-677 help." Accessed May 17, 2026.
- Reddit r/Peptides. "CJC 1295 w/DAC + MK677 combo." Accessed May 17, 2026.
- Reddit r/sarmsourcetalk. "Is there anything mk-677 shouldn't be taken with?" Accessed May 17, 2026.