ACE-031 vs Anastrozole
Emerging vs FDA Approved
synergistic Mechanism-based · 46% Anastrozole supports hormonal recovery from suppression caused by ACE-031. Standard protocol — begin PCT after the suppressive compound has cleared based on its half-life.
Molecular Data
ACE-031 Anastrozole
Weight — 293.37 Da
Half-life 12-15 days ~40-50 hours
Type Soluble activin receptor type IIB-Fc fusion protein Nonsteroidal aromatase inhibitor (triazole derivative)
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
Anastrozole
01 Potent reduction of circulating estradiol levels (70-80% at standard dose)
02 Prevents gynecomastia during testosterone or anabolic steroid cycles
03 Reduces estrogen-driven water retention and bloating
04 Helps control estrogen-related blood pressure elevation
05 Oral dosing with long half-life allows flexible scheduling (EOD or E3D)
06 Reversible inhibition allows estrogen recovery after discontinuation
07 Well-characterized pharmacokinetics with decades of clinical data
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
Anastrozole
0.25-0.5mg EOD or E3D (estrogen management) / Every other day to every 3 days (cycle support); daily (breast cancer)
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
Anastrozole
Joint pain, stiffness, or dryness (from reduced estrogen-mediated joint lubrication)
Hot flashes or flushing
Fatigue and general malaise
Mood changes (flat affect, irritability, or low mood)
Decreased libido (when estrogen is suppressed too aggressively)
Headache
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
Known hypersensitivity to anastrozole or any excipients
Premenopausal women (not indicated and potentially harmful to reproductive function)
Pregnancy or breastfeeding (teratogenic risk)
Severe hepatic impairment
Pre-existing severe osteoporosis or high fracture risk
Concurrent use with tamoxifen or estrogen-containing therapies
Research Evidence
ACE-031 Anastrozole
Status Emerging FDA Approved
References 4 studies 5 studies
FDA Approved No Yes
This comparison is for educational and research purposes only. Consult a healthcare professional before use.