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Home/Compounds/MK-677
Growth hormone

MK-677

Also known as: Ibutamoren · MK-0677 · Nutrobal

Orally active non-peptide ghrelin receptor agonist that increases GH and IGF-1; investigational, never approved.

B
Grade B
Human observational studies
Human studies25
PubMed citations30
Routeoral
Regulatory (US)Research only
Last verified2 days ago

Mechanism of action

Small-molecule agonist of the ghrelin receptor (GHSR1a). Stimulates GH and IGF-1 secretion from pituitary and activates appetite pathways.

Evidence summary

25
Human studies
30
PubMed citations
8
Clinical trials
B
Evidence grade

Multiple clinical trials by Merck in the 1990s–2000s explored indications including hip fracture recovery and frailty. Not pursued to approval.

Dosing protocols

Educational information only. Consult a licensed provider before using any peptide.
Administration routes
oral

Side effects & safety

No FDA label or editorial side-effect profile is on file for this compound yet. See the clinical trials and citations sections for study-reported safety data.

Interactions

No documented drug interactions on file.

Regulatory status

United States
Not FDA approved

Not FDA approved. Sold widely online as a research chemical; not a dietary supplement ingredient under US law.

Compounding
Not permitted

Not available via 503A/503B compounding pharmacies.

Regulatory data last verified 4/19/2026

Clinical trials

NCT06948214A Multicenter, 12-Month, Randomized, Double Blind, Placebo-Controlled Phase 3 Efficacy and Safety Study of Daily Oral LUM-201 in Naïve-to-Treatment, Prepubertal Children With Growth Hormone Deficiency (GHD)Recruiting · Phase 3 · Growth Hormone Deficiency (GHD) · n=150NCT05364684The Impact of Ibutamoren on Nonalcoholic Fatty Liver Disease: A Pilot StudyCompleted · Phase 2 · NAFLD · n=12NCT01343641A Phase 2, Investigator-Initiated, Randomized, Double-Blind, Placebo-Controlled Study to Determine Growth Hormone Secretagogue MK-0677's Effect on Lean Body Mass in Chronic Kidney Disease Subjects With Stage 4 and Stage 5 Kidney DiseaseWithdrawn · Phase 2 · Chronic Kidney DiseaseNCT00395291Growth Hormone Secretagogue MK-0677 Effect on IGF-1 Levels in ESRD PatientsCompleted · N/A · Chronic Kidney Disease · n=49NCT00128115Proprietary Information - Exploratory (Non-Confirmatory) TrialTerminated · Phase 2 · Hip Fracture · n=83NCT00074529A Randomized, Double-Blind, Placebo-Controlled Trial to Evaluate the Safety and Efficacy of MK-0677 25 mg in Slowing the Progression of Alzheimer's DiseaseCompleted · Phase 2 · Alzheimer's Disease · n=512NCT00116129A Randomized, Double-Blind, Placebo-Controlled Trial to Evaluate the Safety and Efficacy of MK-0677 25 mg in the Treatment of Primary FibromyalgiaCompleted · Phase 2 · Fibromyalgia · n=64NCT00474279Effects of an Oral GH Secretagogue (MK-677) on Body Composition and Functional Ability of Older AdultsCompleted · Phase 1 · Aging · n=72

Citations

PMID 41693185Stawerska R · New directions in growth hormone treatment in children.Pediatric endocrinology, diabetes, and metabolism (2026)HumanPMID 40091212Xu H, Liu M et al. · Design, Biological Characterization, and Discovery of Capromorelin Derivatives as Oral Growth Hormone Secretagogue Receptor Type 1a Agonist for the Treatment of Growth Hormone Deficiency.Journal of medicinal chemistry (2025)HumanPMID 39145153Chong S, Woolnough CA et al. · Reversible Gynecomastia and Hypogonadism Due to Usage of Commercial Performance-Enhancing Supplement Use.JCEM case reports (2024)HumanPMID 39668330Abdul Ghafoor N, Rasuli S et al. · Investigating the P53-dependent anti-cancer effect of ibutamoren in human cancer cell lines.Basic & clinical pharmacology & toxicology (2024)HumanPMID 36354265Viljanto M, Cutler C et al. · Detection of the growth hormone secretagogue MK-0677 in equine hair following oral administration.Drug testing and analysis (2023)HumanPMID 34542924Philip M, Karakka Kal AK et al. · Characterization of equine liver microsome-generated metabolites of growth hormone secretagogue small molecule ibutamoren.Rapid communications in mass spectrometry : RCM (2022)HumanPMID 36303408Cardaci TD, Machek SB et al. · LGD-4033 and MK-677 use impacts body composition, circulating biomarkers, and skeletal muscle androgenic hormone and receptor content: A case report.Experimental physiology (2022)HumanPMID 34737341Liu H, Sun D et al. · Structural basis of human ghrelin receptor signaling by ghrelin and the synthetic agonist ibutamoren.Nature communications (2021)HumanPMID 32257855Sinha DK, Balasubramanian A et al. · Beyond the androgen receptor: the role of growth hormone secretagogues in the modern management of body composition in hypogonadal males.Translational andrology and urology (2020)HumanPMID 30450851Lee J, Kwon A et al. · Effect of the Orally Active Growth Hormone Secretagogue MK-677 on Somatic Growth in Rats.Yonsei medical journal (2019)HumanPMID 28340044Campbell GA, Patrie JT et al. · Oral ghrelin receptor agonist MK-0677 increases serum insulin-like growth factor 1 in hemodialysis patients: a randomized blinded study.Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association (2019)HumanPMID 28400207Sigalos JT, Pastuszak AW · The Safety and Efficacy of Growth Hormone Secretagogues.Sexual medicine reviews (2018)HumanPMID 19455266Tomillero A, Moral MA · Gateways to clinical trials.Methods and findings in experimental and clinical pharmacology (2009)HumanPMID 19015485Sevigny JJ, Ryan JM et al. · Growth hormone secretagogue MK-677: no clinical effect on AD progression in a randomized trial.Neurology (2008)HumanPMID 17200730Bayes M, Rabasseda X et al. · Gateways to clinical trials.Methods and findings in experimental and clinical pharmacology (2007)HumanPMID 15261841Smith RG, Sun Y et al. · Growth hormone secretagogues: prospects and potential pitfalls.Best practice & research. Clinical endocrinology & metabolism (2005)HumanPMID 15066065Bach MA, Rockwood K et al. · The effects of MK-0677, an oral growth hormone secretagogue, in patients with hip fracture.Journal of the American Geriatrics Society (2004)HumanPMID 14610293Camiña JP, Carreira MC et al. · Regulation of ghrelin secretion and action.Endocrine (2004)HumanPMID 11452249Codner E, Cassorla F et al. · Effects of oral administration of ibutamoren mesylate, a nonpeptide growth hormone secretagogue, on the growth hormone-insulin-like growth factor I axis in growth hormone-deficient children.Clinical pharmacology and therapeutics (2001)HumanPMID 10592437Smith RG, Palyha OC et al. · Growth hormone releasing substances: types and their receptors.Hormone research (2000)Human

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