ACE-031
Myostatin pathway inhibitor via decoy receptor — Phase II muscle mass gains halted due to vascular side effects.
Research facts
| Half-life | ~14 days |
|---|---|
| Route | SubQ / IV |
| Typical dose | 1–3 mg/kg (Phase II dose) |
| Frequency | Once every 2 weeks |
| Solvent | Commercial formulation |
| pH | N/A |
| Stability | Refrigerated |
Mechanism of action
ACE-031 is a fusion protein consisting of the extracellular domain of activin receptor type IIB (ACVR2B) linked to an IgG1 Fc region. It acts as a ligand trap — binding and sequestering multiple TGF-β family members including myostatin, activin A/B, GDF-11, and BMP-9. By preventing these ligands from binding their endogenous receptors, it removes the growth-inhibitory signals on skeletal muscle. Phase II trials in Duchenne muscular dystrophy demonstrated significant lean mass increases (muscle hypertrophy). However, the trial was halted due to unexpected vascular side effects: telangiectasias (dilated capillaries) and nosebleeds, attributed to inhibition of BMP-9 which maintains vascular integrity.
Documented effects (research-model)
- Significant lean mass increase demonstrated in Phase II RCT
- Myostatin pathway blockade via decoy receptor mechanism
- Broader inhibitory profile than pure anti-myostatin antibodies
- Research tool for understanding TGF-β family biology
Research protocols
| Protocol | Dose | Frequency | Cycle | Vial |
|---|---|---|---|---|
| Historical Phase II | 1–3 mg/kg every 2 weeks IV/SubQ | Biweekly | Trial halted — no current research protocol | N/A — not available as research peptide |
Research context only. Not medical advice. Consult a qualified healthcare professional before any protocol decision.
Synergies
No documented synergies in the current reference set.
Myths & misconceptions
Evidence gaps
- Whether vascular side effects are dose-dependent or mechanism-related.
- More selective myostatin inhibitors (e.g. anti-myostatin antibodies) have been developed to avoid BMP-9 co-inhibition.
Safety notes
HALTED: Clinical trials were stopped due to vascular adverse events. Not recommended for research use. Educational profile only.
Biomarkers to monitor
Primary-source citations
- PMID 24166931 — ACE-031 treatment of Duchenne muscular dystrophy: results of a randomised, double-blind, placebo-controlled trial (Muscle Nerve. 2013)
Frequently asked
What is ACE-031?
ACE-031 (ACVR2B-Fc — Activin Receptor Type IIB Fusion Protein) is a research compound classified in our library as Tier C — Limited human trials; effect size uncertain.. Myostatin pathway inhibitor via decoy receptor — Phase II muscle mass gains halted due to vascular side effects.
What is the evidence tier for ACE-031?
We classify ACE-031 as Tier C: Limited human trials; effect size uncertain. See our full peptide evidence tiers explainer for how we assign S/A/B/C/D.
What is the research dose of ACE-031?
For ACE-031, typical research dose is 1–3 mg/kg (Phase II dose), route is SubQ / IV, half-life is ~14 days. Protocols vary by research goal — see the protocols section on this page for standard and advanced dosing schedules. Research use only, not medical advice.
Is ACE-031 safe?
HALTED: Clinical trials were stopped due to vascular adverse events. Not recommended for research use. Research context only — no compound on this site is approved for human therapeutic use unless explicitly noted.