MK-677
Also known as: MK-677, Ibutamoren, MK-0677
An orally active, non-peptide ghrelin receptor agonist that raises GH and IGF-1 levels. Notable for being a daily oral compound rather than an injectable.
Last updated
Mechanism of Action
MK-677 (ibutamoren) is a non-peptide growth hormone secretagogue that mimics ghrelin at the GHS-R1a receptor, stimulating sustained increases in growth hormone and IGF-1. Unlike injectable peptides, it is orally bioavailable and has a long half-life, producing prolonged elevation rather than a sharp pulse. This sustained signaling drives its characteristic appetite stimulation and effects on body composition and sleep.
- Half-life
- Approximately 4-6 hours (effects on IGF-1 persist longer)
- Administration Routes
- oral
- Research Status
- Research Chemical
Reported Benefits
- Oral administration (no injections)
- Sustained elevation of GH and IGF-1
- Increased appetite (useful in research on wasting)
- Improved sleep quality and slow-wave sleep
- Supports lean mass and bone density in studies
- Long half-life allows once-daily dosing
Potential Side Effects
- Significant water retention and bloating
- Increased appetite, sometimes substantial
- Lethargy or grogginess
- Reduced insulin sensitivity / elevated blood glucose
- Numbness or tingling in extremities
Common Dosing
Research literature commonly references ~10-25 mg once daily, frequently dosed before bed. Educational range only, not medical advice.
The dosing information above is aggregated from research literature and anecdotal community reports for educational purposes only. It is not a recommendation, prescription, or medical advice. Peptides are sold as research chemicals only and are not intended for human use.
Contraindications
- Diabetes or impaired glucose tolerance
- Active malignancy
- Congestive heart failure (fluid retention concern)
- Pregnancy or breastfeeding
CJC-1295
A long-acting growth hormone releasing hormone (GHRH) analog that stimulates the pituitary to produce more growth hormone. Often paired with a ghrelin mimetic for synergistic GH release.
Ipamorelin
A selective ghrelin receptor agonist (growth hormone secretagogue) prized for stimulating GH release with minimal effect on cortisol or prolactin. Considered one of the gentler GH peptides.
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MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism
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Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial
2008
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Design and biological activities of L-163,191 (MK-0677): a potent, orally active growth hormone secretagogue
1995
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MK-0677 (ibutamoren mesylate) for the treatment of patients recovering from hip fracture: a multicenter, randomized, placebo-controlled phase IIb study
2011