ACE-031 vs YK-11
Emerging vs Limited Research
monitor Researched · 90% Both target the myostatin pathway. YK-11 acts as a myostatin inhibitor through a different mechanism. Combined use could produce excessive pathway suppression with unpredictable effects.
Molecular Data
ACE-031 YK-11
Weight — 430.54 Da
Half-life 12-15 days ~6-10 hours
Type Soluble activin receptor type IIB-Fc fusion protein Steroidal selective androgen receptor modulator with myostatin-inhibiting properties (C25H34O6)
Key Benefits
ACE-031
01 Significant lean mass increases (up to 1.7% in 29 days) observed in Phase 1 trials
02 Simultaneous reduction in fat mass alongside muscle gains
03 Long half-life (12-15 days) allows infrequent dosing
04 Broad TGF-beta ligand neutralization for robust anti-catabolic effects
05 Dose-dependent increases in thigh muscle volume confirmed by MRI
YK-11
01 Dual mechanism combining partial AR agonism with myostatin inhibition via follistatin upregulation
02 May theoretically promote muscle growth beyond what AR activation alone can achieve by removing myostatin-mediated growth limits
03 Steroidal structure providing oral bioavailability without requiring injection
04 Partial AR agonist activity may confer tissue selectivity with reduced androgenic side effects compared to full agonists (theoretical, not demonstrated in vivo)
05 Short half-life allows for relatively rapid clearance if side effects necessitate discontinuation
Dosing Protocols
ACE-031
0.5-3 mg/kg IV every 2 weeks (clinical research doses only) / Every 2 weeks
Phase 1 Research Protocol (Healthy Volunteers) 0.1-3 mg/kg Single IV dose
Phase 2 Research Protocol (DMD) 0.5-2.5 mg/kg Every 2 weeks
YK-11
5-10 mg/day / Twice daily (AM/PM split, oral)
Side Effects
ACE-031
Nosebleeds (epistaxis) - most frequently reported adverse event
Gum bleeding
Telangiectasia (dilated small blood vessels visible on skin)
Skin erythema (redness)
Minor injection site reactions
YK-11
Liver stress and enzyme elevation (ALT, AST) due to 17-alpha alkylated steroidal structure
Testosterone suppression (dose- and duration-dependent, expected in all users)
Joint dryness and discomfort (related to reduced estrogenic activity and potential drying effect)
Hair shedding (consistent with androgenic activity from the DHT-derived structure; may or may not be reversible)
Lipid disruption (HDL suppression, LDL elevation)
Reduced libido and mood changes secondary to hormonal suppression
Mild headaches, particularly during the first week
Contraindications
NEVER approved for human use - clinical development discontinued
History of bleeding disorders or vascular malformations
Concurrent anticoagulant or antiplatelet therapy
Known hypersensitivity to Fc fusion proteins
Pregnancy or breastfeeding
Pre-existing liver disease or elevated liver enzymes at baseline (17-alpha alkylated compounds are contraindicated in hepatic impairment)
Hormone-sensitive cancers (prostate cancer or other androgen-responsive malignancies)
Pregnancy or potential pregnancy (teratogenic risk from androgen receptor agonism and hormonal disruption)
Breastfeeding
Age under 25 (incomplete endocrine system maturation and higher risk of lasting HPG axis disruption)
Concurrent use of other hepatotoxic compounds or medications (oral steroids, certain NSAIDs, statins, etc.)
Known cardiovascular disease (insufficient safety data)
Research Evidence
ACE-031 YK-11
Status Emerging Limited Research
References 4 studies 4 studies
Latest — 2013
FDA Approved No No
More comparisons: MK-677
This comparison is for educational and research purposes only. Consult a healthcare professional before use.