Side-by-side · Research reference

ACE-031vsSemaglutide

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 2HUMAN-REVIEWED10/44 cited

BFDA-ApprovedFlagship15/53 cited

ACE-031

ActRIIB-Fc Fusion · Phase 2 Halted

Phase 2Highest trial stage

2011Development halted

~58.4 kDaMolecular weightReichel 2025

SQ · Weekly dosing investigated

Semaglutide

GLP-1 RA · FDA-Approved

0.25–2.4 mgWeekly doseWEGOVY (semaglutide) injection 2021

14.9%Body-weight ↓Wilding 2021

~7 daysHalf-lifeWEGOVY (semaglutide) injection 2021

SQ · Abdomen / thigh / arm · Once weekly

01Mechanism of Action

Parameter

ACE-031

Semaglutide

Primary target

Myostatin, GDF11, activin A — TGF-β superfamily ligands

GLP-1 receptor (GLP-1R)WEGOVY (semaglutide) injection 2021

Pathway

Soluble decoy receptor binds circulating myostatin/TGF-β ligands → prevents ActRIIB activation → SMAD2/3 pathway inhibition

GLP-1R agonism → ↑glucose-dependent insulin secretion, ↓glucagon, ↓gastric emptying, ↓appetite via hypothalamic centresWilding 2021

Downstream effect

Disinhibition of myogenic signaling, increased skeletal muscle mass and strength

Improved glycemic control, reduced caloric intake, body-weight reduction, cardiovascular risk reductionWilding 2021

Feedback intact?

—

Glucose-dependent insulin release preserves physiological feedback

Origin

Recombinant fusion protein: human ActRIIB extracellular domain + IgG1-Fc fragmentReichel 2025

Modified GLP-1(7-37) with two amino-acid substitutions and C-18 fatty-acid acylation for albumin binding and 168-h half-lifeWEGOVY (semaglutide) injection 2021

Antibody development

—

02Dosage Protocols

Parameter

ACE-031

Semaglutide

Clinical dosing

Weekly or biweekly SQ injections (exact doses undisclosed pre-halt)

Phase 2 DMD trial protocol not fully published.

—

Black market products

Variable purity; 12/14 tested products contained target protein plus contaminantsReichel 2025

SDS-PAGE revealed multiple protein bands; quality control absent.Reichel 2025

—

Evidence basis

Phase 2 trial discontinued — incomplete dataset

FDA-approved · Phase 3 RCTsWilding 2021 WEGOVY (semaglutide) injection 2021

Half-life

Days to weeks (Fc-fusion typical kinetics)

IgG1-Fc domain confers extended circulation time.

~7 days (168 h)WEGOVY (semaglutide) injection 2021

Duration investigated

12–24 weeks (trial cut short)

—

Standard dose (T2D, Ozempic)

—

0.5–1.0 mg / weekWEGOVY (semaglutide) injection 2021

Standard dose (weight, Wegovy)

—

2.4 mg / week (after 16-wk titration)WEGOVY (semaglutide) injection 2021 Wilding 2021

Frequency

—

Once weekly, same day each week

Titration schedule

—

0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg over 16 weeks

Mitigates GI side effects.

Duration

—

Indefinite for chronic indication

Discontinuation results in weight regain.

Reconstitution

—

Pre-mixed pen device (commercial). Research lyophilised vial: bacteriostatic water per label.

Timing

—

Any time of day, with or without food

04Side Effects & Safety

Parameter

ACE-031

Semaglutide

Epistaxis (nosebleeds)

Significant incidence in Phase 2 DMD trial — primary safety signal

—

Telangiectasia

Dilated capillaries / spider veins observed

—

Vascular abnormalities

Mechanism: ActRIIB/ALK1 pathway disruption affects vascular homeostasis

—

Injection site reactions

Local erythema, induration (biologics class effect)

—

Antibody development

Potential for anti-drug antibodies (Fc-fusion proteins); incidence not reported

—

Black market contaminants

12/14 tested products contained multiple unidentified proteins alongside ACE-031Reichel 2025

—

GI symptoms

—

Nausea, vomiting, diarrhea, constipation (very common)Wilding 2021

Injection site reaction

—

Mild erythema, pruritus

Pancreatitis risk

—

Rare; discontinue if suspectedWEGOVY (semaglutide) injection 2021

Thyroid C-cell tumours

—

Boxed warning — contraindicated in MEN2 / personal or family MTC historyWEGOVY (semaglutide) injection 2021

Hypoglycemia

—

Low risk as monotherapy; elevated when combined with sulfonylureas / insulin

Gallbladder events

—

Increased cholelithiasis

Pregnancy / OB

—

ContraindicatedWEGOVY (semaglutide) injection 2021

Heart rate

—

Modest ↑ resting HR (~2-4 bpm)

Absolute Contraindications

ACE-031

·History of vascular disorders (epistaxis, telangiectasia, HHT)
·Pregnancy (TGF-β pathway critical for fetal development)
·Active malignancy (myostatin inhibition may affect tumour growth)
·Use of non-pharmaceutical grade ACE-031 (contamination risk)Reichel 2025

Semaglutide

·Personal or family history of medullary thyroid carcinoma
·Multiple endocrine neoplasia syndrome type 2
·Pregnancy / breastfeeding
·Hypersensitivity to semaglutide

Relative Contraindications

ACE-031

·Coagulation disorders or anticoagulant use (epistaxis risk)
·Hereditary hemorrhagic telangiectasia (HHT) family history
·Cardiovascular disease (vascular remodeling effects unknown)

Semaglutide

·Severe gastroparesis
·History of pancreatitis
·Diabetic retinopathy (may worsen with rapid glycemic improvement)

05Administration Protocol

Parameter

ACE-031

Semaglutide

1. Pharmaceutical status

ACE-031 is not FDA-approved or commercially available. Phase 2 development was discontinued in 2011 due to safety concerns. Any ACE-031 on the black market is unregulated research chemical.

Commercial: pre-filled pen, no reconstitution. Research vial: per-label or bacteriostatic water.

2. Black market quality

12 of 14 tested black market ACE-031 products contained the target protein but also carried multiple unidentified protein contaminants detectable by SDS-PAGE. Two products contained no ACVR2B-immunoreactive material.Reichel 2025

SQ — abdomen, thigh, or upper arm. Rotate sites weekly to avoid lipohypertrophy.

3. Detection in sport

ACE-031 is prohibited under WADA S4.3 (Myostatin Inhibitors). Gel electrophoresis and Western blotting using ACVR2B-specific antibodies can detect the ~58.4 kDa protein in biological samples.Reichel 2025

Once weekly, same day. Day can be changed if ≥2 days separate doses.

4. Clinical trial route

Phase 2 protocol used subcutaneous injections at weekly or biweekly intervals. Exact dosing protocols remain unpublished.

Pen: refrigerate 2–8 °C unopened; room temp ≤30 °C up to 56 days after first use.

5. Needle

—

Pen-supplied 31–34G needle. Research vial: 27–31G insulin syringe.

06Stack Synergy

ACE-031

— no documented stacks

Semaglutide

+ Tirzepatide

Weak

View Tirzepatide →

Combining two GLP-1 RA-class drugs is not clinically validated and risks additive GI toxicity. Tirzepatide's GIP component already provides complementary mechanism vs pure GLP-1; stacking with semaglutide adds receptor saturation but no synergy. NOT recommended.

Note: Stack not recommended — choose one GLP-1 RA
Primary benefit: (none — additive toxicity, no synergy)