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Peptide Profile
Ibutamoren · MK-0677 · Nutrobal
MK-677 (ibutamoren; ibutamoren mesylate) is an orally active, non-peptide small-molecule ghrelin receptor (GHS-R1a) agonist developed by Merck as a research compound for GH deficiency and muscle-wasting conditions, notable as one…
Educational research information — not medical advice. Review primary sources and consult a qualified professional before any decision.
Educational research tools — not medical advice.
MK-677 mimics the action of ghrelin by binding to and activating the GHSR-1a receptor in the pituitary gland, stimulating pulsatile GH release. Its oral bioavailability distinguishes it from peptide-based GH secretagogues and its prolonged half-life results in sustained IGF-1 elevation. Research protocols have explored its effects on lean body mass, bone mineral density, and sleep architecture.
MK-677 (ibutamoren; ibutamoren mesylate) is an orally active, non-peptide small-molecule ghrelin receptor (GHS-R1a) agonist developed by Merck as a research compound for GH deficiency and muscle-wasting conditions, notable as one of the few GH secretagogues with confirmed oral bioavailability and a substantial human clinical dataset spanning multiple Phase 2 randomized controlled trials. MK-677 mimics ghrelin to stimulate pulsatile GH and IGF-1 secretion from the pituitary in a dose-dependent manner without directly replacing GH, and RCTs have demonstrated significant increases in fat-free mass and GH secretion in obese adults and in hemodialysis patients with nutritional deficits, establishing the pharmacology of oral GHS-R1a agonism in humans. Despite robust human pharmacological evidence, MK-677 was not advanced to FDA registration; Merck Phase 3 trials showed efficacy on surrogate endpoints but did not demonstrate the clinical outcomes required for approval, commercial development was discontinued, and no approved indication exists. MK-677 is a non-peptide research compound — not a peptide in the pharmacological sense — with no FDA approval; it is widely available through research chemical suppliers and used off-label, and considerations including its documented effects on insulin sensitivity, fasting glucose, and sustained IGF-1 elevation are relevant to its risk profile. MK-677 dosage in clinical trials: published RCTs studied oral doses of 10 mg, 25 mg, and 50 mg once daily. The timing of administration relative to sleep has been explored in some studies in relation to the natural nocturnal GH peak. MK-677's oral bioavailability is a practical distinction from injectable GH secretagogues — it is administered as a tablet or capsule without the reconstitution steps required for peptide injectables. Side effects documented in RCTs include increased appetite (a direct ghrelin-mimetic effect), mild peripheral edema from water retention, and transient increases in fasting blood glucose — a clinically relevant finding for individuals with pre-existing insulin sensitivity concerns. Sustained IGF-1 elevation from long-duration use is a differentiated risk characteristic compared to short-half-life injectable GHRPs. MK-677 is sometimes grouped with performance peptides due to overlapping research contexts but is pharmacologically a non-peptide small molecule. Licensed telehealth and anti-aging providers who carry growth hormone secretagogues are listed in the PeptideBase directory.
Commonly researched in the context of
Population research notes
These signals reflect research interest areas, not treatment indications.
Compound & timing
Model: single-dose, first-order (single-compartment) estimate. Real clearance is multi-compartment and varies by individual and route.
based on 2 studies · 2 RCTs · most recent 2018
Non-peptide ghrelin mimetic. Active IND; Phase 2/3 trials by Merck/Helsinn. Never FDA-approved. FDA enforcement actions against MK-677 supplements as unapproved new drug. Investigational only.
Regulatory status reflects publicly available information and may change. This is not legal or medical advice.
2 sources cited · 2 strong
2 RCTs
Oral ghrelin receptor agonist MK-0677 increases serum insulin-like growth factor 1 in hemodialysis patients: a randomized blinded study
Nephrology, Dialysis, Transplantation · 2018
Research in a 3-month randomized crossover trial found that oral MK-0677 produced a 65% greater increase in serum IGF-1 compared with placebo in hemodialysis patients, with no serious adverse effects, providing evidence for the GH secretagogue pathway as a potential approach to protein-energy wasting in chronic kidney disease.
Two-month treatment of obese subjects with the oral growth hormone (GH) secretagogue MK-677 increases GH secretion, fat-free mass, and energy expenditure
Journal of Clinical Endocrinology and Metabolism · 1998
Research in an 8-week randomized placebo-controlled trial found that oral MK-677 25 mg daily increased serum IGF-I by approximately 40%, significantly increased fat-free mass as measured by dual-energy X-ray absorptiometry, and transiently increased basal metabolic rate in obese men, without significant changes in total or visceral fat.
No FDA-approved label for this compound. Cautions below are extrapolated from its mechanism/drug class — investigational; educational only.
Warnings & cautions
Class-based (investigational)
Consult a qualified healthcare professional before making any health decisions. This information is educational only and does not constitute medical advice.
MK-677 · Lot Test-HG2 · Jun 19, 2026 · View source COA
PeptideBase reports these lab-published figures and does not itself test, endorse, or certify any product. Verified results come from an independent third-party lab database lookup. Vendor-published results are reported by the vendor itself and have not been independently verified by PeptideBase or a third-party lab.
PeptideBase provides educational research tools and provider discovery. It does not provide medical advice, diagnosis, treatment, prescribing guidance, or dosing instructions. Consult a qualified healthcare professional before making health decisions.
Self-reported, anecdotal experiences aggregated from public Reddit discussions — community sentiment, not clinical evidence or medical advice.
Outcome distribution
Side effects people mention
Counts are mentions across reports, not incidence rates.
Most reported
What they wish they'd known
Based on 14 community reports · Updated
MK-677 (ibutamoren; ibutamoren mesylate) is an orally active, non-peptide small-molecule ghrelin receptor (GHS-R1a) agonist developed by Merck as a research compound for GH deficiency and muscle-wasting conditions, notable as one of the few GH secretagogues with confirmed oral bioavailability and a substantial human clinical dataset spanning multiple Phase 2 randomized controlled trials. MK-677 mimics ghrelin to stimulate pulsatile GH and IGF-1 secretion from the pituitary in a dose-dependent manner without directly replacing GH, and RCTs have demonstrated significant increases in fat-free mass and GH secretion in obese adults and in hemodialysis patients with nutritional deficits, establishing the pharmacology of oral GHS-R1a agonism in humans.
oral GH and IGF-1 stimulation without injection, fat-free mass increase documented in RCTs, appetite stimulation via ghrelin receptor agonism, sustained IGF-1 elevation — long-duration monitoring relevant.
Research on MK-677 primarily documents effects related to oral GH and IGF-1 stimulation without injection and fat-free mass increase documented in RCTs and appetite stimulation via ghrelin receptor agonism and sustained IGF-1 elevation — long-duration monitoring relevant. These are areas covered in preclinical and clinical literature — individual response varies and effects depend on context of use.
Reported contraindications and considerations for MK-677 include Active malignancy — caution (raises GH/IGF-1), Pregnancy — caution, Uncontrolled diabetes / insulin resistance (can raise fasting glucose). 1 additional consideration are noted in the safety profile above. This is educational information only — consult a qualified healthcare professional before use.
For MK-677, its FDA status is banned from compounding by the FDA, and it is designated for research use only. Regulatory status reflects publicly available information and may change. This is not legal or medical advice.
48 providers in the directory currently offer MK-677.
Across 9 research vendors tracked on PeptideBase, MK-677 has a median price of about $6.57 per mg, typically ranging $3.67–$8.00 per mg. This reflects research-use vendor pricing, not clinical or prescription costs.
Research in a 3-month randomized crossover trial found that oral MK-0677 produced a 65% greater increase in serum IGF-1 compared with placebo in hemodialysis patients, with no serious adverse effects, providing evidence for the GH secretagogue pathway as a potential approach to protein-energy wasting in chronic kidney disease.
MK-677 is featured in the following research stacks on PeptideBase: MK-677 + Epithalon: Sleep Architecture & Anti-Aging.
Price per mg varies by quantity, vendor type, and formulation. Research use only.
Data verified July 2026 · MK-677 price intelligence
Functional Medicine Partners
Gameday Men's Health
iLIFE Anti-Aging Center
Medispa At Choto
T Clinics USA
The Perito Clinic
Virtus Health Optimization
Wellness IV Infusion Therapy
Absolute Hormone
Commonly stacked with
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Data last updated July 20, 2026
Free to reference and republish with attribution to PeptideBase. Choose a format:
PeptideBase. (2026). MK-677 — Per-mg Price Benchmark. Retrieved July 22, 2026, from https://peptidebase.io/peptides/mk-677