MK-677 vs Proviron
Well Studied vs Well Studied
avoid Mechanism-based · 64% Both MK-677 and Proviron carry hepatotoxic risk. Combining hepatotoxic compounds significantly increases liver damage potential. If unavoidable, include liver support (TUDCA/NAC) and monitor ALT/AST frequently.
Molecular Data
MK-677 Proviron
Weight 624.77 Da 304.47 Da
Half-life ~24 hours ~12 hours
Type Non-peptide ghrelin receptor agonist DHT derivative (C20H32O2)
Key Benefits
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)
Proviron
01 Strong SHBG binding frees more circulating testosterone, enhancing TRT efficacy
02 Improved mood, motivation, confidence, and overall sense of well-being
03 Significant enhancement of libido and sexual function
04 Anti-estrogenic effect reduces the need for dedicated aromatase inhibitors
05 Harder, drier, more defined physical appearance without water retention
06 Minimal hepatotoxicity due to absence of 17-alpha alkylation
07 May improve sperm quality at low doses in subfertile men
08 Rapid onset of subjective well-being effects (often within days)
Side Effects
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.
Proviron
Accelerated hair thinning or loss in those predisposed to male pattern baldness (DHT-mediated)
Mild suppression of endogenous testosterone at higher doses (though less suppressive than most AAS)
Oily skin and increased sebum production
Mild HDL cholesterol suppression with extended use
Increased body hair growth
Contraindications
Heart disease or congestive heart failure
Diabetes or pre-diabetes
Active cancer
Severe cardiovascular disease
Pregnancy or breastfeeding
Prostate cancer (active or history of androgen-sensitive prostate cancer)
Severe liver impairment (though hepatotoxicity risk is minimal)
Breast cancer in males
Hypersensitivity to mesterolone or any excipients
Women who are pregnant or may become pregnant (androgenic effects on fetus)
Research Evidence
MK-677 Proviron
Status Well Studied Well Studied
References 7 studies 5 studies
Latest July 2024 —
FDA Approved No No
This comparison is for educational and research purposes only. Consult a healthcare professional before use.