Human RCT-level evidence

Ibutamoren

What the research and the regulators actually say, sourced to primary documents.

Studies indexed
0
Clinical trials
0
Last updated
July 23, 2026

Updated · sourced to primary documents

Research information only, not medical advice. Ibutamoren (MK-677) is an orally active, nonpeptide ghrelin receptor agonist (a growth hormone secretagogue) that raises growth hormone and IGF-1 levels. It is not approved by the FDA for any indication and remains investigational, with no approved labeling. It is sold only as an unapproved "research chemical" and is prohibited in sport by the World Anti-Doping Agency.

Ibutamoren at a glance

Clinical evidence is limited to small-to-moderate trials focused on GH/IGF-1 and body composition. In a randomized, double-blind, placebo-controlled trial in healthy older adults, once-daily oral MK-677 raised GH and IGF-1 toward levels seen in healthy young adults and significantly increased fat-free mass versus placebo over one year (Nass et al., Ann Intern Med 2008;149:601-611, PMID 18981485). In a randomized controlled trial in patients with mild-to-moderate Alzheimer disease, MK-677 raised IGF-1 but did not slow disease progression versus placebo (Sevigny et al., Neurology 2008, PMID 19015485). Mechanistically, ibutamoren mimics the action of ghrelin at the GHS-R1a receptor, stimulating pulsatile growth hormone release without suppressing endogenous secretion. Reported effects in trials include increased appetite, transient rises in blood glucose with reduced insulin sensitivity, and fluid retention or edema; long-term safety has not been established (Nass et al., 2008).

See how we grade evidence for the methodology behind this page.

Evidence profile

56 studies
  • Human RCT 2 · 4%
  • Human trial 8 · 14%
  • Review 6 · 11%
  • Animal 10 · 18%
  • In-vitro 8 · 14%
  • Unknown 22 · 39%

The longer the green, the stronger the human evidence. For most research peptides the bar is dominated by animal and in-vitro work, which is a signal to read every claim carefully.

Regulatory status

Clinical trials

  • NCT00074529 PHASE2 COMPLETED

    Study of MK0677 for the Treatment of Alzheimer's Disease (0677-030)(COMPLETED)

  • NCT00116129 PHASE2 COMPLETED

    Efficacy and Safety of an Oral Growth Hormone Drug in the Treatment of Fibromyalgia

  • NCT00128115 PHASE2 TERMINATED

    Treatment of Sarcopenia in Post-Hip Fracture Patients (0677-032)

  • NCT00395291 NA COMPLETED

    Growth Hormone Secretagogue MK-0677 Effect on IGF-1 Levels in ESRD Patients

  • NCT00474279 PHASE1, PHASE2 COMPLETED

    Effects of an Oral GH Secretagogue (MK-677) on Body Composition and Functional Ability of Older Adults

  • NCT01343641 PHASE2 WITHDRAWN

    Growth Hormone Secretagogue MK-0677's Effect on Lean Body Mass in Chronic Kidney Disease Stage 4/5 Subjects

  • NCT05364684 PHASE2 COMPLETED

    The Impact of Ibutamoren on Nonalcoholic Fatty Liver Disease

  • NCT06948214 PHASE3 RECRUITING

    Phase 3 Study of LUM-201 in Children With Growth Hormone Deficiency

Indexed research

Sorted by evidence level, strongest first.

+ 46 more studies indexed for Ibutamoren.

Frequently asked questions

Is Ibutamoren approved for human use?
Ibutamoren (MK-677) is an orally active, nonpeptide ghrelin receptor agonist (a growth hormone secretagogue) that raises growth hormone and IGF-1 levels. It is not approved by the FDA for any indication and remains investigational, with no approved labeling. It is sold only as an unapproved "research chemical" and is prohibited in sport by the World Anti-Doping Agency.
What does the research on Ibutamoren show?
Clinical evidence is limited to small-to-moderate trials focused on GH/IGF-1 and body composition. In a randomized, double-blind, placebo-controlled trial in healthy older adults, once-daily oral MK-677 raised GH and IGF-1 toward levels seen in healthy young adults and significantly increased fat-free mass versus placebo over one year (Nass et al., Ann Intern Med 2008;149:601-611, PMID 18981485). In a randomized controlled trial in patients with mild-to-moderate Alzheimer disease, MK-677 raised IGF-1 but did not slow disease progression versus placebo (Sevigny et al., Neurology 2008, PMID 19015485). Mechanistically, ibutamoren mimics the action of ghrelin at the GHS-R1a receptor, stimulating pulsatile growth hormone release without suppressing endogenous secretion. Reported effects in trials include increased appetite, transient rises in blood glucose with reduced insulin sensitivity, and fluid retention or edema; long-term safety has not been established (Nass et al., 2008).