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COMPOUNDS / PEPTIDE / MK-677
PEPTIDE

MK-677

MEDIUM RISK
BEST FOR:Recovery●●●●●●●○○○7/10
MK-677 · IBUTAMOREN · IBUTAMOREN MESYLATE · MK-0677 · L-163,191
Growth Hormone SecretagogueGhrelin MimeticPerformanceSleepAnti-Catabolic

Orally active growth hormone secretagogue that stimulates GH and IGF-I release, used for muscle growth and improved sleep.

ROUTE / DOSAGE
LOW5mg
STANDARD10-25mg
HIGH50mg+
Note: 25mg once daily is the most studied dose; take at bedtime for sleep benefits
CYCLE
4-8 weeks on 4 weeks off
BIOAVAILABILITY
~60% oral
ACTIVE DURATION
24h+ (subjective)
STORAGE
Room temperature dry away from light
HALF-LIFE
~24h (plasma)
DURATION BREAKDOWN
Total24h+
Onset30min-1h
Come up1-2h
Peak2-6h
Offset6-12h
After effects12-24h
Duration varies by route, dose, and individual. Source: community reports.
§ 01 — EFFECTS
8 documented
Increased growth hormone secretion
Elevated IGF-I levels
Improved nitrogen retention and lean mass
Increased appetite
Enhanced sleep quality (stage IV and REM)
Increased bone turnover markers
Water retention and edema
Potential muscle strength improvement
§ 02 — RISKS
Hepatotoxicity (transaminitis) documented in a 2025 case report
Decreased insulin sensitivity and elevated blood glucose
Edema and water retention
Desensitization of GH response with prolonged use
Testosterone suppression and adverse lipid changes when co-administered with SARMs
Increased bone resorption markers without clear BMD benefit at most sites
§ 03 — INTERACTIONS
Interaction data not yet available for this compound.
§ 04 — SCIENCE

Clinical trials demonstrate that MK-677 (25 mg/day) significantly increases GH and IGF-I levels, improves nitrogen balance in catabolic states, increases bone turnover markers, and enhances sleep quality in both young and elderly subjects. A 2025 case report documented drug-induced hepatotoxicity (transaminitis) in a healthy male after 2 months of use, which resolved upon discontinuation. Co-administration with LGD-4033 in a case study showed negative impacts on liver enzymes, serum lipids, testosterone, and bone mineral density. A rat study found that prolonged MK-677 administration led to desensitization of the GH response via upregulated hypothalamic somatostatin, with no net growth promotion after 6 weeks. Long-term safety data, including cancer incidence and mortality, remain insufficient.

§ 06 — SOURCES
[1]
MK-677 reverses diet-induced catabolism (1998)
pubmed.ncbi.nlm.nih.gov ↗
[2]
Hepatotoxicity induced by MK-677 (2025)
pubmed.ncbi.nlm.nih.gov ↗
[3]
LGD-4033 and MK-677 use impacts body composition and biomarkers (2022)
pubmed.ncbi.nlm.nih.gov ↗
[4]
MK-677 increases markers of bone turnover in elderly adults (1999)
pubmed.ncbi.nlm.nih.gov ↗
[5]
Safety and efficacy of growth hormone secretagogues (2018)
pubmed.ncbi.nlm.nih.gov ↗
[6]
Effect of MK-677 on somatic growth in rats (2018)
pubmed.ncbi.nlm.nih.gov ↗
[7]
Alendronate and MK-677 effects on bone mineral density (2001)
pubmed.ncbi.nlm.nih.gov ↗
[8]
MK-677 improves sleep quality in man (1997)
pubmed.ncbi.nlm.nih.gov ↗
Disclaimer. Protokol.wiki is an informational reference. Nothing on this site is medical advice. Compounds listed may be unapproved, unregulated, or illegal in your jurisdiction. Consult a licensed physician before use. Data compiled from peer-reviewed literature.
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