Side-by-side · Research reference

ACE-031vsSelank

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

BHuman-MechanisticAUTO-DRAFTED11/40 cited

ACE-031

ActRIIB-Fc Fusion · Phase 2 Halted

Phase 2Highest trial stage

2011Development halted

~58.4 kDaMolecular weightReichel 2025

SQ · Weekly dosing investigated

Selank

Anxiolytic + Cognitive · Russian Pharma

150–300 mcg/doseIntranasalZaderej 2014

HumanMechanisticZaderej 2014 Medvedev 2007

~30 minOnset

Intranasal · 2–3×/day during stress / cognitive demand

01Mechanism of Action

Parameter

ACE-031

Selank

Primary target

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

Monoamine system (serotonin / GABA modulation) + immunomodulation via tuftsin domainZaderej 2014

Pathway

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

Tuftsin-derived immune signaling + CNS monoamine modulation → reduced anxiety + improved mood / cognitionMedvedev 2007

Downstream effect

Disinhibition of myogenic signaling, increased skeletal muscle mass and strength

Anxiolytic + cognitive enhancement; immunomodulation via increased IL-6 + IFN-γMedvedev 2007 Zaderej 2014

Feedback intact?

—

No GABA-receptor binding; no dependence reportedMedvedev 2007

Origin

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

Synthetic 7-AA peptide derived from human tuftsin (immune-system tetrapeptide)Zaderej 2014

Antibody development

—

02Dosage Protocols

Parameter

ACE-031

Selank

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

Human-mechanistic + Russian clinical trialsMedvedev 2007

Half-life

Days to weeks (Fc-fusion typical kinetics)

IgG1-Fc domain confers extended circulation time.

Short (minutes plasma); CNS effect lasts ~3 hr

Duration investigated

12–24 weeks (trial cut short)

—

Standard dose

—

150–300 mcg / dose intranasalZaderej 2014

Frequency

—

2–3× per day during stress

Lower / starter dose

—

75 mcg / dose

Duration

—

10–14 day cycles, repeated as needed

Reconstitution

—

Pre-formulated nasal spray (commercial); research vial: bacteriostatic water

Timing

—

Morning + early afternoon preferred

04Side Effects & Safety

Parameter

ACE-031

Selank

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

—

Nasal irritation

—

Mild burning or congestion (transient)

Sedation

—

None — distinct from benzodiazepinesMedvedev 2007

Dependence / withdrawal

—

None reported in clinical useZaderej 2014

Cognitive impairment

—

None — opposite effect (enhancement)

Allergic reaction

—

Rare hypersensitivity

Long-term safety

—

Limited Western RCT data

Pregnancy / OB

—

Avoid — insufficient 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

Selank

·Pregnancy / breastfeeding
·Hypersensitivity to peptide

Relative Contraindications

ACE-031

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

Selank

·Active autoimmune disease (theoretical via immunomodulation)

05Administration Protocol

Parameter

ACE-031

Selank

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.

Pre-formulated nasal spray (commercial) or research vial reconstituted with 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

Intranasal — 1–3 sprays per nostril per dose. Tilt head slightly back.

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

Morning + early afternoon for cognitive demand; PRN for acute anxiety.

4. Clinical trial route

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

Refrigerate after reconstitution; ≤30 days. Light-protected.

5. Caveat

—

Avoid co-administration with strong sedatives or other anxiolytics initially.