ACE-031 Overview
Mechanism of Action
ACE-031 is a soluble activin receptor type IIB-Fc fusion protein acting as a decoy receptor. It binds and neutralizes myostatin, activin A, GDF-11, and other TGF-β ligands that inhibit muscle growth. By sequestering these negative regulators, it removes the ‘brakes’ on muscle development.
~10–14 days (Fc fusion)
Timing
No specific timing
Injection Site
Subcutaneous
Food
No restrictions
Common Stacks
- BPC-157/TB-500 — Recovery support for tissue remodeling
ACE-031 Dosing Protocol
Standard Protocol
8–12 weeks0.1–0.3 mg SQ every 2 weeks
Limited human safety data.
ACE-031 Expected Timeline
Week 1–2
Myostatin suppression begins
Week 4–6
Initial lean mass gains
Week 8–12
Significant muscle mass increase
ACE-031 Side Effects
Minor nosebleeds
Gum bleeding
Dilated blood vessels
Limited human safety data
ACE-031 Research Studies
ACE-031 increases bone and muscle mass in healthy postmenopausal women
Attie KM, et al. — J Bone Miner Res (2013)
Phase 2 study: single dose increased lean body mass by up to 3.3% and thigh muscle volume.
PubMed: 23322328ACE-031 FAQ
Is ACE-031 safe?
Early trials showed promising muscle effects but paused due to minor vascular side effects (nosebleeds, telangiectasias) related to BMP-9/10 binding.
How does it compare to GDF-8 propeptide?
ACE-031 blocks myostatin PLUS activin A, GDF-11. GDF-8 propeptide targets only myostatin. ACE-031 is broader but may have more side effects.