Side-by-side · Research reference
ACE-031vsAdipotide
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
BAnimal-StrongHUMAN-REVIEWED15/49 cited
ACE-031
ActRIIB-Fc Fusion · Phase 2 Halted
SQ · Weekly dosing investigated
Adipotide
Pro-apoptotic Vascular-Targeting Peptide · Preclinical Only
IV · Systemic · Preclinical Protocols OnlyHossen 2013
01Mechanism of Action
Parameter
ACE-031
Adipotide
Primary target
Myostatin, GDF11, activin A — TGF-β superfamily ligands
Prohibitin-1 (PHB1) on adipose vasculature endotheliumHossen 2013
Pathway
Soluble decoy receptor binds circulating myostatin/TGF-β ligands → prevents ActRIIB activation → SMAD2/3 pathway inhibition
CKGGRAKDC domain binds PHB1 → Peptide internalisation → D(KLAKLAK)₂ mitochondrial membrane disruption
Downstream effect
Disinhibition of myogenic signaling, increased skeletal muscle mass and strength
Endothelial apoptosis → Adipose vascular collapse → Adipocyte involution → Weight loss
Feedback intact?
—
N/A — Direct apoptotic mechanism, non-hormonal
Origin
Recombinant fusion protein: human ActRIIB extracellular domain + IgG1-Fc fragmentReichel 2025
Synthetic bioconjugate: PHB1-targeting homing peptide + pro-apoptotic KLA sequence
Antibody development
—
—
02Dosage Protocols
Parameter
ACE-031
Adipotide
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
Preclinical animal models only
Half-life
Days to weeks (Fc-fusion typical kinetics)
IgG1-Fc domain confers extended circulation time.
—
Duration investigated
12–24 weeks (trial cut short)
—
Animal dose (mouse)
—
Low dose (not specified in abstract)Hossen 2013
Systemic injection in diet-induced obesity (DIO) models.Hossen 2013
Route
—
Intravenous (systemic injection)
Frequency
—
Not specified in available data
Human data
—
None — no clinical trials reported
03Metabolic / Fat Loss Evidence
Parameter
ACE-031
Adipotide
Primary fat target
—
White adipose tissue (all depots)
Body weight reduction
—
Significant reduction in DIO miceHossen 2013
Absolute values not provided in abstract.
Leptin levels
—
Significant decrease
Parallel to adipose mass reduction.
Effect on adipocytes
—
Antiobesity effect on dysfunctional adipose cells (adipocytes + macrophages)Hossen 2013
Ectopic fat
—
Reduction in ectopic fat depositionHossen 2013
Marker of dysfunctional adipose tissue / metabolic syndrome.
Species tested
—
Obese rhesus monkeys, DIO mice
Human translation
—
Unknown — no clinical trials
04Side Effects & Safety
Parameter
ACE-031
Adipotide
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
—
Safety profile
—
Unknown — preclinical data only
Vascular selectivity
—
Targets adipose vasculature; off-target vascular effects unknown
Apoptotic mechanism risk
—
Pro-apoptotic payload may affect unintended tissues if selectivity incomplete
Kidney / liver toxicity
—
Not reported in available data
Immunogenicity
—
Not assessed in available data
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
Adipotide
- ·Human use — not approved, no clinical safety data
Relative Contraindications
ACE-031
- ·Coagulation disorders or anticoagulant use (epistaxis risk)
- ·Hereditary hemorrhagic telangiectasia (HHT) family history
- ·Cardiovascular disease (vascular remodeling effects unknown)
Adipotide
- ·Any condition requiring intact adipose-tissue vascularisation
05Administration Protocol
Parameter
ACE-031
Adipotide
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.
Intravenous injection (systemic) in preclinical models. No human protocols exist.
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
Bioconjugate peptide. May also be encapsulated in nanoparticles (prohibitin-targeted nanoparticle formulation, KLA-PTNP, showed superior efficacy vs. free bioconjugate in mice).Hossen 2013
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
Low-dose systemic injection (exact dosing not specified in available abstract). Frequency and duration not detailed.Hossen 2013
4. Clinical trial route
Phase 2 protocol used subcutaneous injections at weekly or biweekly intervals. Exact dosing protocols remain unpublished.
Not specified — likely requires peptide-grade lyophilised storage and reconstitution.