Hexarelin vs MK-677
Well Studied vs Well Studied
monitor Mechanism-based · 51% Both Hexarelin and MK-677 stimulate the ghrelin receptor. Additive GH release may increase side effects (water retention, joint pain, blood glucose elevation). Consider using one at a time or reducing doses.
Molecular Data
Hexarelin MK-677
Weight 887 Da 624.77 Da
Half-life 1-2 hours ~24 hours
Chain 6 amino acids —
Type Synthetic hexapeptide Non-peptide ghrelin receptor agonist
Key Benefits
Hexarelin
01 Most potent GHRP for GH stimulation
02 Powerful synergy with GHRH peptides
03 Cardioprotective effects via CD36 receptor
04 Enhanced muscle growth and strength
05 Improved fat metabolism
06 Better recovery and tissue repair
07 Maintains natural GH pulsatility
08 Stable against proteolytic enzymes
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
Hexarelin
100-200 mcg per injection / 2-3 times daily for optimal GH pulses
GH optimization 100 mcg 2-3x daily
Enhanced results 200 mcg 2-3x daily
With GHRH (synergy) 100 mcg each 2-3x daily
Cardioprotection 100-200 mcg 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
Hexarelin
Increased appetite (less than GHRP-6)
Water retention
Tingling or numbness
Tiredness after injection
Mild headache
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
Active cancer or history of cancer
Pregnancy or breastfeeding
Pituitary disorders
WADA prohibited for competitive athletes
Heart disease or congestive heart failure
Diabetes or pre-diabetes
Active cancer
Severe cardiovascular disease
Pregnancy or breastfeeding
Research Evidence
Hexarelin MK-677
Status Well Studied Well Studied
References 4 studies 7 studies
Latest — July 2024
FDA Approved No No
This comparison is for educational and research purposes only. Consult a healthcare professional before use.