GHK-Cu vs MK-677
Well Studied vs Well Studied
synergistic Mechanism-based · 47% GHK-Cu and MK-677 work through complementary pathways. Growth hormone signaling supports tissue repair processes. A well-established combination in recovery protocols.
Molecular Data
GHK-Cu MK-677
Weight 404.96 Da 624.77 Da
Half-life 0.5-2 hours ~24 hours
Chain 3 amino acids —
Type Copper tripeptide Non-peptide ghrelin receptor agonist
Key Benefits
GHK-Cu
01 Enhanced collagen production (70% increase in type I and III)
02 Improved skin elasticity
03 Reduced fine lines and wrinkles
04 Accelerated wound healing
05 Hair growth stimulation
06 Antioxidant protection
MK-677
01 97% increase in 24-hour growth hormone secretion
02 40-72% elevation in IGF-1 levels
03 Enhanced sleep quality with improved REM patterns
04 Preferential lean tissue gains of 1.1-2.7kg over 8-12 months
05 15% basal metabolic rate increase within 2 weeks
06 Oral administration (no injections required)
Dosing Protocols
GHK-Cu
0.5-2% topical or 1-3mg injectable / 1-2x daily
Systemic anti-aging 1-2mg 1x daily
Enhanced regeneration 2-3mg 1-2x daily
MK-677
Start 12.5mg daily, increase to 25mg based on tolerance / Once daily, preferably at bedtime on empty stomach
Side Effects
GHK-Cu
Mild skin irritation initially (usually resolves)
Increased photosensitivity
MK-677
Appetite stimulation (>50% of users)
Water retention (30-40%)
Lethargy (20-30%)
Fasting glucose elevation (5-15mg/dL)
Note on testosterone suppression: at doses up to 20 mg daily, MK-677 is unlikely to cause significant testosterone suppression on its own. Above 20 mg daily, the likelihood of suppression and other side effects (insulin resistance, water retention, lethargy) increases. The case report documenting 85.7% testosterone suppression involved co-administration with LGD-4033, a SARM known to be profoundly suppressive, making the SARM the likely primary driver of that suppression.
Contraindications
Known copper sensitivity or Wilson's disease
Active skin infections at application site
Pregnancy or breastfeeding (injectable)
Heart disease or congestive heart failure
Diabetes or pre-diabetes
Active cancer
Severe cardiovascular disease
Pregnancy or breastfeeding
Research Evidence
GHK-Cu MK-677
Status Well Studied Well Studied
References 5 studies 7 studies
Latest July 2025 July 2024
FDA Approved No No
This comparison is for educational and research purposes only. Consult a healthcare professional before use.