What it is
ACE-031 is a peptide that functions as a myostatin inhibitor by acting as a decoy soluble form of the activin type IIB receptor. By neutralising myostatin and related ligands, it can promote increased muscle mass and strength and is of interest in muscle-wasting conditions and athletic recovery research. Animal models also suggest a positive effect on bone density.
Mechanism of action
Recombinant fusion protein of the activin receptor IIB (ActRIIB) extracellular domain and an IgG Fc fragment. Binds and sequesters myostatin (GDF-8) and related TGF-β family ligands, preventing receptor activation and disinhibiting muscle hypertrophy pathways.
Half-life: Long — antibody-like Fc fusion, half-life on the order of 10–15 days.
Evidence summary
Phase 1 healthy-volunteer data (Attie 2013) demonstrated dose-dependent lean-mass increases. Phase 2 in Duchenne muscular dystrophy was halted for non-muscle adverse events. Marmoset and analytical work continues to characterise the molecule.
Typical dosing protocols
- Investigational only — published trials used 0.5–3 mg/kg IV/SC
- Dosing every 2–4 weeks given long half-life
- Not currently available as an approved therapeutic
Side effects & safety
- Reported in trials: epistaxis, telangiectasia, skin rash, gingival bleeding
- Vascular adverse events led to early termination of Duchenne Phase 2
- Long-term safety not established
Cited studies
- Attie KM, Borgstein NG, Yang Y, et al. (2013). A single ascending-dose study of muscle regulator ACE-031 in healthy volunteers. Muscle & Nerve.Read source ↗
- (2017). Myostatin inhibitor ACE-031 treatment of ambulatory boys with Duchenne muscular dystrophy: Results of a randomized, placebo-controlled clinical trial. Muscle & Nerve.Read source ↗
- (2026). ACE-031, a soluble activin type IIB receptor, increases muscle mass and strength in the common marmoset (Callithrix jacchus). PLOS ONE.Read source ↗
- (2025). Gel Electrophoretic Detection of Black Market ACE-031. Drug Testing and Analysis.Read source ↗
All content is for research and educational purposes. Peptides described are sold for laboratory research use only and are not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional before beginning any protocol.
