ACE-031

ACE-031 is a soluble form of the activin type IIB receptor (ActRIIB) fused to a human IgG1 Fc domain (MW ~90,000 g/mol). It functions as a ligand trap, sequestering myostatin, activin, GDF-11, and other TGF-beta superfamily members that signal through ActRIIB to suppress muscle growth. Acceleron Pharma conducted Phase I and Phase II clinical trials in Duchenne muscular dystrophy (DMD) before discontinuing development due to vascular safety signals (nosebleeds, telangiectasias).

1 independent Janoshik purity test cover ACE-031 across 1 vendor.

Category: Muscle Growth / Research. Evidence rating: C (early/mixed human evidence).

Clinical status: Phase I/II completed (DMD). Development discontinued by Acceleron Pharma (2013) due to vascular adverse events. Successor programs (ACE-083, local) also discontinued.

ACE-031 is a decoy receptor — it mimics the natural ActRIIB receptor and binds myostatin, activin A/B, GDF-11, and BMP-9/10 before they can engage cell-surface receptors. By trapping these ligands in the circulation, it prevents downstream Smad2/3 signaling that would otherwise inhibit muscle…

Safety considerations: CRITICAL: Vascular safety signals led to clinical discontinuation; Epistaxis (nosebleeds) in multiple subjects; Telangiectasias (dilated blood vessels in skin/mucosa).

Reviewed by the PeptideAtlas Editorial Team.

ACE-031 — measured properties

Molecular weight~90,000 g/mol (Fc-fusion protein)
Half-life~10-14 days (Fc-mediated FcRn recycling)
Bioavailability~50-80% SC (large protein)
Production methodrecombinant
Anti-doping statusProhibited in sport (WADA)
US regulatory statusDevelopment discontinued (Acceleron Pharma, 2013). Not FDA-approved. Available only as research chemical.

ACE-031 third-party purity tests

VendorBest tested purity
Inno Peptides99.2%

Related peptides: Follistatin-315.

Frequently asked questions

Why was ACE-031 discontinued?

Despite impressive muscle-building results, ACE-031 caused vascular side effects (nosebleeds, telangiectasias) because it trapped BMP-9 and BMP-10 in addition to myostatin. These BMPs are essential for vascular homeostasis. More selective myostatin inhibitors are being developed.

Can I actually buy ACE-031?

Products marketed as ACE-031 are almost certainly not authentic. ACE-031 is a complex ~90 kDa Fc-fusion protein that requires mammalian cell expression systems and cannot be made by peptide synthesis. Any vial labeled ACE-031 from a peptide vendor is highly suspect.

What is ACE-031?

ACE-031 is a soluble form of the activin type IIB receptor (ActRIIB) fused to a human IgG1 Fc domain (MW ~90,000 g/mol). It functions as a ligand trap, sequestering myostatin, activin, GDF-11, and other TGF-beta superfamily members that signal through ActRIIB to suppress muscle growth. Acceleron Pharma conducted Phase I and Phase II clinical trials in Duchenne muscular dystrophy (DMD) before…

How strong is the evidence for ACE-031?

On the PeptideAtlas A–F scale, ACE-031 is rated C (Early Evidence). Early human evidence, limited trials, or mixed findings

What is the clinical status of ACE-031?

Phase I/II completed (DMD). Development discontinued by Acceleron Pharma (2013) due to vascular adverse events. Successor programs (ACE-083, local) also discontinued.