Side-by-side · Research reference

ACE-031vsSermorelin

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

BPhase 3HUMAN-REVIEWED14/43 cited

ACE-031

ActRIIB-Fc Fusion · Phase 2 Halted

Phase 2Highest trial stage

2011Development halted

~58.4 kDaMolecular weightReichel 2025

SQ · Weekly dosing investigated

Sermorelin

GHRH 1-29 fragment · Short-acting

100–500 mcgPer doseMolteno 2013

Phase 3Evidence levelWalker 1994 Molteno 2013

~12 minHalf-lifeMolteno 2013

SQ · Pre-sleep · 1×/day

01Mechanism of Action

Parameter

ACE-031

Sermorelin

Primary target

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

Pituitary GHRH receptorWalker 1994

Pathway

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

GHRH-R → Gαs → cAMP → PKA → GH vesicle exocytosisWalker 1994

Downstream effect

Disinhibition of myogenic signaling, increased skeletal muscle mass and strength

Pulsatile GH release; subsequent IGF-1 elevationMolteno 2013

Feedback intact?

—

Yes — short pulse preserves feedback

Origin

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

Unmodified active 29-AA fragment of human GHRH (1-44)Walker 1994

Antibody development

—

02Dosage Protocols

Parameter

ACE-031

Sermorelin

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

Phase 3 (Geref pediatric); clinical practiceWalker 1994 Molteno 2013

Half-life

Days to weeks (Fc-fusion typical kinetics)

IgG1-Fc domain confers extended circulation time.

~12 min (plasma)Molteno 2013

Shorter than tesamorelin (~26 min) — simpler GHRH analogue.

Duration investigated

12–24 weeks (trial cut short)

—

Standard dose

—

100–500 mcg per injectionMolteno 2013

Frequency

—

Once daily, pre-sleep

Lower / starter dose

—

100 mcg per dose

Duration

—

8–12 weeks per cycle

Reconstitution

—

Bacteriostatic water

Timing

—

Pre-sleep, fasted preferred

04Side Effects & Safety

Parameter

ACE-031

Sermorelin

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

—

Injection site reaction

—

Mild erythema, transient pain

Flushing / headache

—

Common transient effect

IGF-1 elevation

—

Modest at standard doses

Cancer risk

—

Contraindicated in active malignancy (GH/IGF-1 axis)

Pregnancy / OB

—

Avoid

Glucose handling

—

Generally neutral

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

Sermorelin

·Active malignancy
·Pregnancy / breastfeeding
·Disrupted hypothalamic-pituitary axis

Relative Contraindications

ACE-031

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

Sermorelin

·Untreated diabetes

05Administration Protocol

Parameter

ACE-031

Sermorelin

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.

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL = 250 mcg per 0.1 mL.

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 or thigh. Rotate sites.

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

Pre-sleep, fasted.

4. Clinical trial route

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

Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.

5. Needle

—

29–31G, 4–8 mm insulin syringe.

06Stack Synergy

ACE-031

— no documented stacks

Sermorelin

+ Ipamorelin

Strong

View Ipamorelin →

Sermorelin (GHRH analogue) and ipamorelin (selective GHRP) form the prototypical GHRH+GHRP dual-axis stack at the lowest cost. Both peak within 30 min and produce a sharp physiological GH pulse without cortisol/prolactin elevation.

Sermorelin: 200–300 mcg SQ · pre-sleep
Ipamorelin: 200–300 mcg SQ · same injection
Primary benefit: Pulsatile GH stimulation, recovery, body composition

Raun 1998 Walker 1994