Masteron vs MK-677
Moderate Research vs Well Studied
monitor Mechanism-based · 51% Both Masteron and MK-677 can raise blood pressure. Monitor BP regularly and consider adding cardiovascular support (cardarine, telmisartan, or similar).
Molecular Data
Masteron MK-677
Weight 304.47 Da (base) 624.77 Da
Half-life ~2 days (propionate), ~10 days (enanthate) ~24 hours
Type DHT-derived anabolic steroid (C20H32O2) Non-peptide ghrelin receptor agonist
Key Benefits
Masteron
01 Produces a hard, dry, and grainy appearance by eliminating subcutaneous water retention
02 Mild anti-estrogenic properties that can reduce or replace the need for aromatase inhibitors on cycle
03 Does not aromatize, eliminating estrogen-mediated side effects from the compound itself
04 Enhances the visual effects of other steroids in a stack by reducing water retention and bloat
05 Modest increases in strength without significant weight gain, useful for weight-class athletes
06 Improves muscle density and vascularity at low body fat percentages
07 Well-tolerated with a relatively mild side effect profile compared to other anabolic steroids
08 Short detection window with propionate ester compared to many other injectable steroids
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
Masteron
300-500 mg/week / Every other day (propionate) or 2x per week (enanthate)
Cutting / Aesthetic Enhancement 300-400 mg/week Every other day (propionate) or 2x per week (enanthate)
Contest Preparation 400-500 mg/week Every other day or daily (propionate)
AI Replacement / Estrogen Management 200-300 mg/week Every other day (propionate) or 2x per week (enanthate)
MK-677
Start 12.5mg daily, increase to 25mg based on tolerance / Once daily, preferably at bedtime on empty stomach
Side Effects
Masteron
Hair loss and accelerated male pattern baldness (significant risk as a DHT derivative - the most commonly reported side effect)
Acne and increased skin oiliness, particularly on the back and shoulders
Suppression of natural testosterone production (requires PCT or ongoing TRT)
Injection site pain or discomfort (more common with propionate ester)
Mild aggression or irritability from elevated androgenic activity
HDL cholesterol suppression and adverse lipid profile changes
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
Prostate cancer (active or history of hormone-sensitive prostate cancer)
Breast cancer in males
Pregnancy or potential for pregnancy (causes virilization of female fetus)
Known hypersensitivity to drostanolone or any formulation components
Severe hepatic impairment
Pre-existing significant hair loss where further androgenic exposure is unacceptable
Polycythemia (hematocrit above 54% at baseline)
Uncontrolled cardiovascular disease or severe dyslipidemia
Heart disease or congestive heart failure
Diabetes or pre-diabetes
Active cancer
Severe cardiovascular disease
Pregnancy or breastfeeding
Research Evidence
Masteron MK-677
Status Moderate Research Well Studied
References 5 studies 7 studies
Latest March 2020 July 2024
FDA Approved No No
This comparison is for educational and research purposes only. Consult a healthcare professional before use.