ACE-031 1mg Dosage & Mixing Guide

What is ACE-031?

ACE-031 (INN ramatercept) is a soluble activin receptor type IIB fused to a human IgG1-Fc arm — an engineered decoy that mops up myostatin, activin A and related TGF-beta ligands before they can reach the real receptor. It is the ligand-trap approach to the same pathway that Follistatin-344 addresses from the antagonist side.

Strictly speaking it is a fusion protein, not a peptide. It ships in the PeptiMap catalogue under the category rule settled on 2026-07-22: the qualifying test is whether the lyophilised-vial, reconstitution-and-syringe template applies, not molecular class. It does, so here it is.

Two things make this page worth reading before the arithmetic: what the multi-week half-life actually attaches to, and how a 1mg vial compares to the doses humans were given. Both are covered under Research Considerations.

Reconstitution

ACE-031 reconstitutes with bacteriostatic water. Draw the water down the inside wall of the vial, swirl gently until fully dissolved, and refrigerate. Do not shake — Fc-fusion proteins are large and aggregate readily under mechanical stress, and foaming is the visible sign of that.

A 1mg vial is a small amount of protein spread over the bottom of the vial, so it can be hard to see the powder at all. Add the water slowly and give it a few minutes before deciding whether anything is left undissolved.

Quick Reference

Reconstitution Guide

Materials Needed

• ACE-031 1mg lyophilized vial
• Bacteriostatic water (BAC water)
• Insulin syringes (U-100, 29-31 gauge)
• Alcohol swabs
• Sharps container

Step-by-Step Instructions

1. Prepare workspace — Clean environment, gather materials, thorough handwashing.
2. Clean vial stoppers — Wipe both vials with alcohol swabs. Allow complete drying.
3. Draw BAC water — Draw 1mL bacteriostatic water using a sterile syringe.
4. Add to peptide — Inject slowly down the inside wall of the vial. Do not spray directly onto the powder.
5. Dissolve — Allow a few minutes for complete dissolution. Gentle swirl only — no shaking, and no foaming.
6. Verify — Solution should be clear and free of visible particles.
7. Label and store — Note the reconstitution date and the final concentration. Refrigerate immediately.

Dosage Protocol

Concentration Calculations

With 1mg protein in 1mL BAC water:

• Concentration: 1mg / 1mL = 1mg/mL (1000mcg/mL)
• Per unit (U-100 syringe): 1000 / 100 = 10mcg per unit

With 1mg protein in 2mL BAC water:

• Concentration: 1mg / 2mL = 0.5mg/mL (500mcg/mL)
• Per unit (U-100 syringe): 500 / 100 = 5mcg per unit

The 2mL fill is worth considering here precisely because the vial is small: doubling the volume halves the concentration and doubles the number of syringe units per unit of protein, which makes small measured fractions of the vial far easier to read off the barrel. Run your own vial and volume combination through the peptide reconstitution calculator to rebuild these tables for your setup.

Common Dose Calculations — 1mL fill (1mg/mL)

Common Dose Calculations — 2mL fill (0.5mg/mL)

At 0.5mg/mL a 500mcg draw fills an entire 1mL U-100 barrel, so anything above that on the 2mL fill needs two draws. That is the usual trade-off between resolution and draw volume — see peptide dosing 101 for how to pick a side.

Research Considerations

Mechanism

The ActRIIB extracellular domain binds myostatin (GDF-8), activin A, GDF-11 and several related ligands with high affinity. Fusing it to an IgG1-Fc arm turns that domain into a circulating sink: ligands bind the decoy instead of membrane-bound ActRIIB, SMAD2/3 signalling drops, and the brake on muscle protein accretion is released. The Fc arm also does the pharmacokinetic work — FcRn recycling is what keeps the construct in circulation for weeks rather than hours.

In the single-dose human study (Attie et al., 2013), 48 healthy postmenopausal women received 0.02-3 mg/kg subcutaneously. Mean elimination half-life was ~10-15 days, with AUC and Cmax rising linearly with dose. The muscle signal — around +3.3% total body lean mass by DXA and +5.1% thigh muscle volume by MRI at day 29 — appeared at the 3 mg/kg level. A later ambulatory Duchenne trial was stopped after the second dosing regimen over epistaxis and telangiectasias, bleeding and vascular findings attributed to broad activin-pathway ligand trapping; development did not continue. There is no approved ACE-031 product in any jurisdiction. Background on what a half-life figure does and does not tell you is in peptide half-life explained.

Sourcing for Research

Source from verified suppliers that provide third-party testing and certificates of analysis (COA) for each batch. Compare purity documentation, shipping conditions, and batch traceability before purchasing research materials. Two ACE-031-specific facts belong in that comparison.

The Fc arm is usually missing. Reichel et al. (Drug Testing and Analysis, 2025) characterised 14 grey-market ACE-031 products by SDS-PAGE, Western blot and mass spectrometry. Twelve contained full-length activin receptor IIB without the IgG1-Fc arm; one contained follistatin-344 instead; one contained no protein at all. Since the 10-15 day half-life is a property of the Fc arm and its FcRn recycling, that figure should not be assumed to describe material sold as ACE-031 — a bare receptor domain has nothing to attach the multi-week persistence to. A COA that reports identity by mass and confirms the fusion, rather than reporting purity alone, is the document that settles this. What a COA actually certifies covers how to read one.

The vial is smaller than the study doses. The lowest dose given in the human trial was 0.02 mg/kg — roughly 1.4mg for a 70kg adult. The dose where the muscle-mass signal appeared was 3 mg/kg, roughly 210mg. A 1mg vial therefore sits below the smallest single dose ever administered in a human study of this construct, and two orders of magnitude below the dose that moved lean mass. That arithmetic is worth doing before comparing per-vial prices, because vial size and study dose are not on the same scale here.

Storage Requirements

Lyophilized (Powder)

• Temperature: -20°C or colder
• Duration: 2+ years
• Conditions: Dry, dark, protected from moisture

Reconstituted

• Temperature: 2-8°C (refrigerated)
• Duration: 2-3 weeks
• Conditions: Protected from light, never freeze

Fc-fusion proteins tolerate freeze-thaw poorly once in solution — aggregates form and do not redissolve. Keep the reconstituted vial refrigerated, at the back of the shelf rather than in the door, and avoid repeated warming.

Safety Considerations

• ACE-031 is a research compound
• Not approved for any indication in any jurisdiction
• Research use only — not for human consumption
• Use sterile technique; never reuse needles or syringes

Scientific References

1. Attie KM, et al. A single ascending-dose study of muscle regulator ACE-031 in healthy volunteers. Muscle Nerve. 2013;47(3):416-423. (PMID 23169607)
2. Campbell C, et al. Myostatin inhibitor ACE-031 treatment of ambulatory boys with Duchenne muscular dystrophy: results of a randomized, placebo-controlled clinical trial. Muscle Nerve. 2017;55(4):458-464. (PMID 27462804)
3. Reichel C, et al. Analysis of black market ACE-031 products. Drug Test Anal. 2025;17(10):1934-1946. (PMID 40312924)

Last updated: 2026-07-22.

Disclaimer: This information is for educational and research purposes only. ACE-031 is a research compound and is not approved for any use. Research-grade peptides are not intended for human consumption. Always follow applicable laws and institutional guidelines.