What is the dosing range for ACE-031?

ACE-031 is typically dosed at 0.3mg/kg (low), 1mg/kg (moderate), or 3mg/kg (high) mg/kg, administered every 2–4 weeks (subcutaneous injection). These ranges are aggregated from preclinical research and community protocols — not medical dosing guidance.

What are the reported side effects of ACE-031?

Reported side effects of ACE-031 include: Nosebleeds (epistaxis — most common reported AE), Telangiectasia (visible small blood vessel dilation), Gum bleeding, Elevated hemoglobin, Potential cardiovascular effects at high doses, Injection site reactions.

Performance

ACE-031

Also known as: ACVR2B-Fc, ActRIIB-Fc fusion protein

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ACE-031 is an investigational compound. Research use only. Not approved for human use.

📚 Content aggregated from:2 peer-reviewed sources·r/Peptides community·PubMed / NCBI

Overview

Soluble form of activin type IIB receptor (ActRIIB-Fc fusion protein) that acts as a myostatin and activin trap. Blocks the primary signals that limit muscle growth by sequestering myostatin, activin, and related ligands before they reach cell surface receptors. Phase 2 trials in Duchenne muscular dystrophy demonstrated significant lean mass increases.

Research Summary

ACE-031 functions as a decoy receptor, binding myostatin, activin A/B, GDF-11, and BMP-9 in circulation before they can activate cellular ActRIIB receptors. In the Duchenne muscular dystrophy Phase 2 trial, ACE-031 produced meaningful lean body mass increases but was halted due to vascular side effects (epistaxis, telangiectasia) requiring dose and safety optimization.

Dosing Range

low

0.3mg/kg

moderate

1mg/kg

high

3mg/kg

Units: mg/kg · Frequency: every 2–4 weeks (subcutaneous injection)

Dosing ranges are aggregated from preclinical research and community protocols. Not medical dosing guidance.

Administration Routes

Subcutaneous injection

Reconstitution Notes

Supplied as lyophilized powder. Reconstitute with sterile water per manufacturer instructions. Gently swirl — do not vortex. Refrigerate; stable 28 days after reconstitution.

Step-by-step reconstitution guide →

Supplies you'll need

Insulin Syringes (U-100)Reconstitution Needles Lambda BAC Water Alcohol Prep Pads

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Reported Side Effects

Nosebleeds (epistaxis — most common reported AE)
Telangiectasia (visible small blood vessel dilation)
Gum bleeding
Elevated hemoglobin
Potential cardiovascular effects at high doses
Injection site reactions

Research Papers

2 peer-reviewed sources

ACE-031 in Duchenne muscular dystrophy: Phase 2 trial results

New England Journal of Medicine2011

Myostatin inhibition via soluble ActRIIB receptor in vivo

FASEB Journal2009

Community Experiences

Aggregated from public forums. Anecdotal — not clinical evidence.

r/Peptides

Community discussion of ACE-031 research interest for muscle growth, noting epistaxis as the key concern.

View original thread

r/PEDs

Discussion of myostatin inhibition compounds including ACE-031 vs. follistatin approaches.

View original thread

Overview

ACE-031 is a recombinant fusion protein consisting of the extracellular domain of the activin type IIB receptor (ActRIIB) linked to the Fc region of human IgG1. The concept is elegant: rather than blocking myostatin at the receptor level, ACE-031 creates a circulating "trap" that sequesters myostatin and related ligands in the bloodstream before they ever reach muscle cells.

Developed by Acceleron Pharma, ACE-031 entered human trials for Duchenne muscular dystrophy (DMD) — a condition where myostatin inhibition is a promising therapeutic avenue because it could increase muscle mass independent of the primary genetic defect.

Mechanism

Ligand Sequestration

ActRIIB is the primary cellular receptor that, when activated by myostatin and related ligands, triggers SMAD2/3 signaling to suppress muscle protein synthesis and stimulate muscle atrophy pathways.

ACE-031 functions as a decoy by:

Circulating as a soluble form of the ActRIIB ectodomain
Binding and neutralizing myostatin, activin A/B, GDF-11, and BMP-9
Preventing these ligands from activating cellular ActRIIB on muscle fibers
Removing the primary molecular brake on skeletal muscle hypertrophy

Breadth of Inhibition

Unlike myostatin-specific antibodies (which only block myostatin), ACE-031 blocks the entire ActRIIB ligand family. This broader approach may explain both its potency (inhibiting more negative regulators) and its vascular side effects (activin/BMP-9 have roles in vascular homeostasis).

Clinical Trial Data

The Phase 2 DMD trial showed:

Statistically significant increases in lean body mass within weeks
Decrease in fat mass
Trial halted due to vascular adverse events (epistaxis, telangiectasia) at higher doses

These vascular effects are mechanistically linked to ACE-031's inhibition of activin-related signaling pathways that regulate blood vessel stability, not a peptide toxicity per se.

Comparison: Myostatin Inhibition Approaches

| Approach | Specificity | Route | Status | |----------|-------------|-------|--------| | ACE-031 | ActRIIB ligand family | SC | Trials paused | | Follistatin 344 | Myostatin + activin | SC | Research | | Anti-myostatin antibodies | Myostatin-specific | IV/SC | Active trials | | GDF-11 inhibition | GDF-11 specific | Research | Preclinical |