MK-677
An orally active growth hormone secretagogue that mimics ghrelin to stimulate GH and IGF-1 release.
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This information is for educational purposes. Peptide therapy should be guided by a licensed healthcare provider. Connect with a Noho clinician
What is MK-677?
MK-677 (Ibutamoren) is a non-peptide, orally active growth hormone secretagogue. While technically not a peptide, it is commonly discussed alongside peptides because it acts on the same ghrelin receptor (GHS-R1a) as peptide secretagogues like Ipamorelin. Its oral bioavailability makes it unique in the GH-optimization space.
Why People Talk About It
Oral GH secretagogue (no injection needed)
ModerateIncreased IGF-1 levels
StrongImproved sleep quality
EmergingMuscle preservation
EmergingHow It Works
MK-677 mimics ghrelin, the hunger hormone, by activating the same receptor. This triggers the pituitary gland to release growth hormone. Unlike injectable peptides, it can be taken orally, which is its main practical advantage.
Common Questions
Safety Information
Common Side Effects
Cautions
- • May worsen insulin resistance
- • Not appropriate for diabetics without careful monitoring
- • Can significantly increase appetite
- • May elevate prolactin in some individuals
What We Don't Know
Long-term metabolic effects, particularly on insulin sensitivity, require further study. It has not received FDA approval.
Published Research
23 studiesEffects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial
The effect of treatment with the oral growth hormone (GH) secretagogue MK-677 on GH isoforms
Effect of alendronate and MK-677 (a growth hormone secretagogue), individually and in combination, on markers of bone turnover and bone mineral density in postmenopausal osteoporotic women
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
Treatment of obese subjects with the oral growth hormone secretagogue MK-677 affects serum concentrations of several lipoproteins, but not lipoprotein(a)
Discrepancy between serum leptin values and total body fat in response to the oral growth hormone secretagogue MK-677
Treatment with the oral growth hormone secretagogue MK-677 increases markers of bone formation and bone resorption in obese young males
Two-month treatment of obese subjects with the oral growth hormone (GH) secretagogue MK-677 increases GH secretion, fat-free mass, and energy expenditure
Oral administration of growth hormone (GH) releasing peptide-mimetic MK-677 stimulates the GH/insulin-like growth factor-I axis in selected GH-deficient adults
Effects of a 7-day treatment with a novel, orally active, growth hormone (GH) secretagogue, MK-677, on 24-hour GH profiles, insulin-like growth factor I, and adrenocortical function in normal young men
Stimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral administration of a GH secretogogue (MK-677) in healthy elderly subjects
Prolonged oral treatment with MK-677, a novel growth hormone secretagogue, improves sleep quality in man
MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism.
MK-0677 (ibutamoren mesylate) for the treatment of patients recovering from hip fracture: a multicenter, randomized, placebo-controlled phase IIb study.
Oral administration of the growth hormone secretagogue MK-677 increases markers of bone turnover in healthy and functionally impaired elderly adults. The MK-677 Study Group.
Growth hormone secretagogue MK-677: no clinical effect on AD progression in a randomized trial.
The Safety and Efficacy of Growth Hormone Secretagogues.
LGD-4033 and MK-677 use impacts body composition, circulating biomarkers, and skeletal muscle androgenic hormone and receptor content: A case report
Characterization of growth hormone secretagogue small molecule ibutamoren (MK-0677) and its possible metabolites in thoroughbred horses for doping control
Structural basis of human ghrelin receptor signaling by ghrelin and the synthetic agonist ibutamoren
Characterization of equine liver microsome-generated metabolites of growth hormone secretagogue small molecule ibutamoren
Effect of the Orally Active Growth Hormone Secretagogue MK-677 on Somatic Growth in Rats
Determination of a novel growth hormone secretagogue (MK-677) in human plasma at picogram levels by liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometry
Always consult a qualified clinician
This information is for educational purposes. Peptide therapy should be guided by a licensed healthcare provider. Connect with a Noho clinician
Research Insights
Related Peptides
Ipamorelin
ModerateBeginnerA selective growth hormone secretagogue that stimulates GH release without significantly affecting cortisol or prolactin.
CJC-1295
ModerateBeginnerA growth hormone-releasing hormone analog that stimulates the pituitary gland to produce more growth hormone.
Sermorelin
StrongBeginnerA growth hormone-releasing hormone analog that was previously FDA-approved for diagnosing GH deficiency in children.
Quick Facts
- Class
- Growth Hormone Secretagogue
- Evidence
- Moderate
- Safety
- Moderate Data
- Updated
- Feb 2026
- Citations
- 23PubMed
Also known as
Tags
Related Goals
Evidence Score
Clinical Trials
View Clinical TrialsLinks to ClinicalTrials.gov for reference. Listing does not imply endorsement.
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