MK-677 vs SLU-PP-332
Well Studied vs Emerging
avoid Mechanism-based · 53% Both MK-677 and SLU-PP-332 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 SLU-PP-332
Weight 624.77 Da 290.32 Da
Half-life ~24 hours Under investigation (no human PK data)
Chain — Non-peptide small molecule
Type Non-peptide ghrelin receptor agonist Synthetic ERR agonist
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)
SLU-PP-332
01 Exercise mimetic effects without physical activity
02 12% weight loss in 28 days
03 70% increased endurance
04 25% enhanced fatty acid oxidation
05 Improved insulin sensitivity
06 Reduced hepatic steatosis
07 Cardiac protection
08 Reversal of age-related mitochondrial dysfunction
Dosing Protocols
MK-677
Start 12.5mg daily, increase to 25mg based on tolerance / Once daily, preferably at bedtime on empty stomach
SLU-PP-332
NO HUMAN DOSE ESTABLISHED (animal studies: 50 mg/kg IP) / Research only - not approved for human use
Standard Metabolic Protocol 50 mg/kg (animal dosing) Twice daily
Acute Exercise Enhancement 50 mg/kg (animal dosing) Single dose 1 hour pre-exercise
Extended Treatment 50 mg/kg (animal dosing) Twice daily for 4-8 weeks
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.
SLU-PP-332
Animal studies show favorable safety with no severe effects at therapeutic doses
Well-tolerated in rodents and canines
No liver, kidney, or cardiac toxicity documented
No lean mass loss
Does not suppress hormones or act as stimulant
Minor plasma cholesterol and liver enzyme changes in some studies
Contraindications
Heart disease or congestive heart failure
Diabetes or pre-diabetes
Active cancer
Severe cardiovascular disease
Pregnancy or breastfeeding
NOT FOR HUMAN USE - no approved human dose
No human clinical trials conducted
Potential interaction with diabetes medications
Research Evidence
MK-677 SLU-PP-332
Status Well Studied Emerging
References 7 studies 4 studies
Latest July 2024 2025
FDA Approved No No
This comparison is for educational and research purposes only. Consult a healthcare professional before use.