MK-677 vs RAD-140
Well Studied vs Emerging
synergistic Researched · 95% MK-677 (Ibutamoren) is frequently stacked with RAD-140. MK-677 increases growth hormone and IGF-1 through ghrelin receptor agonism, complementing the AR-mediated anabolic effects of RAD-140. The combination may enhance lean mass accrual, recovery, and sleep quality. MK-677 does not suppress testosterone, making it a useful adjunct during and after SARM cycles.
Molecular Data
MK-677 RAD-140
Weight 624.77 Da 393.83 Da
Half-life ~24 hours ~60 hours
Type Non-peptide ghrelin receptor agonist Nonsteroidal selective androgen receptor modulator (C20H16ClN5O2)
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)
RAD-140
01 Potent anabolic activity in muscle tissue with high oral bioavailability
02 Tissue-selective action sparing the prostate and other androgen-sensitive organs
03 No aromatization to estrogen (no estrogen-related side effects such as water retention or gynecomastia)
04 No conversion to DHT (reduced risk of hair loss and prostate stimulation compared to testosterone)
05 Long half-life (~60 hours) permitting convenient once-daily oral dosing
06 Neuroprotective properties observed in preclinical models
07 Increased lean body mass and reduced fat mass in preclinical studies
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.
RAD-140
Testosterone suppression (dose-dependent, occurs in virtually all users by week 4-6)
Liver enzyme elevation (ALT, AST increases reported in clinical and anecdotal data)
Hair shedding (temporary, typically resolves after discontinuation)
Headaches (most common in the first 1-2 weeks, often transient)
Nausea (mild, usually with initial doses or on an empty stomach)
Lipid disruption (HDL suppression, LDL elevation)
Mild insomnia or sleep disturbance
Reduced libido and mood changes related to testosterone suppression
Contraindications
Heart disease or congestive heart failure
Diabetes or pre-diabetes
Active cancer
Severe cardiovascular disease
Pregnancy or breastfeeding
Pre-existing liver disease or elevated liver enzymes at baseline
Hormone-sensitive cancers (prostate cancer, certain breast cancers not being treated under clinical supervision)
Pregnancy or potential pregnancy (teratogenic risk from androgen receptor agonism)
Breastfeeding
Age under 25 (incomplete endocrine system maturation and higher risk of HPG axis disruption)
Concurrent use of hepatotoxic medications without medical supervision
Known cardiovascular disease (insufficient safety data for this population)
Research Evidence
MK-677 RAD-140
Status Well Studied Emerging
References 7 studies 5 studies
Latest July 2024 July 2020
FDA Approved No No
This comparison is for educational and research purposes only. Consult a healthcare professional before use.