ACE-031 vs GHRP-6
A neutral, side-by-side comparison of two performance & growth hormone peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
ACE-031
Soluble form of activin type IIB receptor (ActRIIB-Fc fusion protein) that acts as a myostatin and activin trap. Blocks the primary signals that limit muscle growth by sequestering myostatin, activin, and related ligands before they reach cell surface receptors. Phase 2 trials in Duchenne muscular dystrophy demonstrated significant lean mass increases.
Full profileGHRP-6
GHRP-6 is a first-generation synthetic hexapeptide GH secretagogue that strongly stimulates pituitary GH release via ghrelin receptor activation. It is one of the oldest and most well-studied GHRPs, with a large body of research spanning more than three decades. GHRP-6 produces significant GH pulses but is notable for powerfully stimulating appetite — a side effect that can be beneficial for those in a caloric deficit or disadvantageous for those managing body composition.
Full profile| ACE-031 | GHRP-6 | |
|---|---|---|
| Category | Performance & Growth Hormone | Performance & Growth Hormone |
| Also known as | ACVR2B-Fc, ActRIIB-Fc fusion protein | Growth Hormone Releasing Peptide-6, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 |
| Evidence | Investigational (in trials) | Preclinical only |
| Dosing range | 0.3mg/kg–3mg/kg mg/kg, every 2–4 weeks (subcutaneous injection) | 100mcg–300mcg mcg, 1–3 times daily, on an empty stomach |
| Administration | Subcutaneous injection | Subcutaneous injection, Intramuscular injection |
| Key side effects | Nosebleeds (epistaxis — most common reported AE), Telangiectasia (visible small blood vessel dilation), Gum bleeding, Elevated hemoglobin | Strong increase in appetite (most common and notable), Elevated cortisol and prolactin at higher doses, Water retention / bloating, Fatigue at high doses |
| Cited sources | 2 references | 3 references |
Key differences
- Evidence level differs: ACE-031 is investigational (in trials), while GHRP-6 is preclinical only.
- Administration: ACE-031 — Subcutaneous injection; GHRP-6 — Subcutaneous injection, Intramuscular injection.
- Dosing units differ: ACE-031 is dosed in mg/kg, GHRP-6 in mcg — they operate at different scales.
- Frequency: ACE-031 is typically every 2–4 weeks (subcutaneous injection); GHRP-6 is 1–3 times daily, on an empty stomach.
- Research depth: this profile cites 2 sources for ACE-031 vs 3 for GHRP-6.
How each works
ACE-031
ACE-031 functions as a decoy receptor, binding myostatin, activin A/B, GDF-11, and BMP-9 in circulation before they can activate cellular ActRIIB receptors. In the Duchenne muscular dystrophy Phase 2 trial, ACE-031 produced meaningful lean body mass increases but was halted due to vascular side effects (epistaxis, telangiectasia) requiring dose and safety optimization.
GHRP-6
Human studies confirm GHRP-6 robustly elevates GH within 15–30 minutes of injection, with effects diminishing toward baseline within 2–3 hours. Chronic use increases baseline IGF-1. Research also indicates mild stimulation of cortisol and prolactin, particularly at higher doses. Animal models have shown potential cardioprotective, hepatoprotective, and muscle-sparing effects, though human equivalents are not established.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.