ACE-031
Also known as: ACVR2B-Fc
ACE-031 is a soluble fusion protein that blocks myostatin and other growth inhibitors to promote dramatic muscle growth and strength increases.
ACE-031 is a ~115 kDa research peptide. ACE-031 is a soluble fusion protein that blocks myostatin and other growth inhibitors to promote dramatic muscle growth and strength increases.
Also called: ACVR2B-Fc
~115 kDa
Molecular Weight
Daltons
2
Strong Evidence
benefits
3
Studies Cited
peer-reviewed
1-3
Typical Dose
mg/kg
Overview
ACE-031 functions as a decoy receptor that binds to myostatin, activin, and other members of the TGF-β superfamily that normally limit muscle growth. By sequestering these negative regulators, ACE-031 allows muscle tissue to grow beyond natural genetic limitations. Originally developed by Acceleron Pharma for muscular dystrophy treatment, this research compound demonstrated remarkable muscle mass increases in clinical trials before development was halted due to safety concerns. The protein works systemically after injection, making it distinct from localized myostatin inhibitors.
Key Takeaways: ACE-031
- Strongest evidence supports ACE-031 for dramatic muscle mass increases and enhanced strength and power output
- Research doses typically range from 1 to 3 mg/kg via subcutaneous
- 2 benefits with strong evidence, 2 moderate, 2 preliminary
- Half-life: 7-14 days
- 3 cited research studies in this guide
Mechanism of Action
ACE-031 acts as a soluble activin receptor type IIB (ACVR2B) that binds to and neutralizes myostatin, activin A, and GDF11. These proteins normally activate SMAD2/3 signaling pathways that suppress muscle protein synthesis and promote muscle atrophy. By blocking this inhibitory signaling, ACE-031 removes the molecular brakes on muscle growth, leading to enhanced satellite cell activation, increased protein synthesis, and accelerated muscle fiber hypertrophy.
Research Benefits
ACE-031 at a Glance
ACE-031 acts as a soluble activin receptor type IIB (ACVR2B) that binds to and neutralizes myostatin, activin A, and GDF11.
Dramatic Muscle Mass Increases
Strong EvidenceACE-031 can increase muscle mass by 20-30% within weeks by blocking myostatin's growth-limiting effects. Clinical studies showed significant increases in thigh muscle volume and total lean body mass.
Enhanced Strength and Power Output
Strong EvidenceMuscle strength improvements parallel the mass gains, with subjects showing increased grip strength and functional capacity. The larger muscle fibers generated produce greater contractile force.
Accelerated Recovery from Muscle Damage
Moderate EvidenceBy promoting satellite cell proliferation and muscle protein synthesis, ACE-031 speeds recovery from exercise-induced muscle damage and reduces markers of muscle breakdown.
Bone Density Improvements
Moderate EvidenceThe increased muscle mass and mechanical loading from ACE-031 treatment appears to stimulate bone formation and increase bone mineral density in weight-bearing bones.
Improved Muscle Fiber Quality
PreliminaryResearch indicates ACE-031 enhances the oxidative capacity of muscle fibers and improves their resistance to fatigue, potentially through effects on mitochondrial biogenesis.
Metabolic Enhancement
PreliminaryGreater muscle mass increases basal metabolic rate and improves glucose uptake, leading to better insulin sensitivity and fat oxidation capacity.
Research Dosing Protocols
Research Purposes Only: All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
| Research Protocol | Dose Range | Route |
|---|---|---|
| Muscle mass research | 1–3 mg/kg | subcutaneous |
| Strength studies | 2–4 mg/kg | subcutaneous |
Frequency
Every 2-4 weeks
Timing
No specific timing requirements
Cycle Length
8-12 weeks maximum
Research Notes
- 1Dosing is weight-based unlike most peptides
- 2Effects are cumulative and long-lasting
- 3Higher doses increase risk of adverse events
- 4Requires reconstitution from lyophilized powder
- 5Single injections can produce effects lasting weeks
Reconstitution Guide
Standard Reconstitution
Vial Size
50 mg
Bacteriostatic Water
1 mL
Concentration
500 mcg
per 0.1 mL (10 units)
Step-by-Step Guide
Gather Materials
ACE-031 vial, bacteriostatic water, alcohol swabs, insulin syringes.
Equilibrate Temperature
Remove the vial from storage and allow it to reach room temperature (5-10 minutes).
Sanitize
Swab the rubber stopper of both the peptide vial and bacteriostatic water vial with alcohol.
Draw Water
Draw 1 mL of bacteriostatic water into a syringe.
Add Water to Vial
Insert the needle into the peptide vial and direct the water stream against the glass wall — not directly onto the powder.
Mix Gently
Swirl the vial gently until the powder is fully dissolved. Never shake. The solution should be clear and colorless.
Store Properly
Refrigerate at 2-8°C refrigerated. 14 days reconstituted.
Storage Temperature
2-8°C refrigerated
Shelf Life
14 days reconstituted
Important Notes
- •Gently swirl to dissolve, do not shake vigorously
- •Solution should be clear and colorless
- •Protect from light during storage
- •Single-use vials should not be re-entered
- •Allow to reach room temperature before injection
ACE-031 Dosing Calculator
Calculate daily intake, cycle totals, and vials needed with pre-filled protocols →
ACE-031 Reconstitution Calculator
Calculate concentration, syringe units, and doses per vial with auto-filled values →
Safety & Side Effects
Reported Side Effects
- !Injection site reactions and swelling
- !Nosebleeds and minor bleeding episodes
- !Headaches and dizziness
- !Muscle cramps and joint stiffness
- !Elevated blood pressure
- !Fluid retention and edema
- !Potential cardiac hypertrophy with long-term use
- !Risk of thrombotic events
- !Possible immune reactions to the fusion protein
Potential Interactions
- ⚡May enhance effects of anabolic steroids
- ⚡Could interfere with TGF-β pathway medications
- ⚡Potential interactions with growth hormone therapy
- ⚡May affect insulin sensitivity and diabetes medications
- ⚡Could interact with blood thinners due to bleeding risk
Important: Side effects and interactions listed here are compiled from published research and community reports. This is not a complete list. No formal drug interaction studies have been conducted for most research peptides. Always consult a qualified healthcare provider.
Research Studies
The following studies are referenced in this profile. PubMed IDs are provided where available for independent verification.
Safety, tolerability, pharmacokinetics, and pharmacodynamics of ACE-031 in healthy volunteers
Phase I study demonstrated dose-dependent increases in muscle mass and strength, with some subjects showing concerning side effects including nosebleeds and elevated blood pressure.
ACE-031, a soluble activin receptor, improves muscle mass and strength in a mouse model of muscular dystrophy
Preclinical study showing significant muscle mass increases and functional improvements in dystrophic mice, establishing proof of concept for therapeutic applications.
Myostatin inhibition in muscle, but not adipose tissue, decreases fat mass and improves insulin sensitivity
Research examining how myostatin pathway inhibition affects body composition and metabolic parameters beyond just muscle growth effects.
Note: This is not an exhaustive list of all published research. Studies are selected for relevance and quality. Click PubMed IDs to verify sources independently. Inclusion does not imply endorsement of the peptide for any clinical use.
Frequently Asked Questions
A single injection can produce muscle-building effects for 2-4 weeks due to its long half-life and the lasting nature of muscle protein synthesis changes. Peak effects typically occur 7-14 days post-injection.
Acceleron Pharma halted development after Phase II trials revealed concerning side effects including nosebleeds, elevated blood pressure, and other safety issues that outweighed the muscle-building benefits for therapeutic use.
ACE-031 may be more potent than peptide myostatin inhibitors because it blocks multiple growth inhibitors simultaneously, but this also increases the risk profile compared to more selective approaches.
The muscle gained from ACE-031 requires ongoing protein synthesis to maintain. Without continued treatment, muscle mass will gradually return toward baseline levels over several months.
Unlike anabolic steroids or growth hormone, ACE-031 works by removing natural growth limitations rather than adding growth signals. This creates a unique mechanism that can produce dramatic results but also unpredictable effects.
Measurable muscle mass increases can occur within 1-2 weeks, with peak effects typically seen at 2-4 weeks post-injection. The rapid onset distinguishes it from slower-acting muscle-building compounds.
ACE-031 carries significant safety concerns that led to discontinued clinical development. Research use requires careful monitoring for cardiovascular effects, bleeding issues, and other adverse events documented in human trials.
Given its long duration of action and safety concerns, ACE-031 is typically used in short cycles of 8-12 weeks maximum with extended breaks between cycles to allow for safety assessment.
Research & Educational Use Only
All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
The information presented here is compiled from published research studies and is intended for informational purposes only. Individual results may vary. Always consult with a licensed healthcare provider.