Other · 1mg × 10 vials
In plain terms: ACE-031 is a research compound - injectable, long-acting and well studied.
ACE-031 (originally developed by Acceleron Pharma, later given the generic name Ramatercept) is a recombinant fusion protein built from the extracellular ligand-binding domain of the human activin receptor type IIB (ActRIIB) fused to the Fc region of a human IgG1 antibody. It is engineered as a soluble decoy. In normal physiology, myostatin (GDF-8), activin A, and several other TGF-beta superfamily ligands bind to ActRIIB on the surface of muscle cells and trigger a Smad2/3 signaling cascade that puts the brakes on muscle growth. Myostatin's job is to cap how much muscle a body will build. ACE-031 floats free in circulation, presents the same ActRIIB binding surface as the membrane receptor, and intercepts (sequesters or "traps") myostatin and activin ligands before they can reach the actual cell-surface receptor. With the brake-pedal ligands neutralized, Smad signaling drops, muscle protein synthesis pathways (mTOR, Akt) get released, and net anabolic balance increases. The result in preclinical models was rapid, substantial increases in lean mass, muscle fiber cross-sectional area, and grip strength, with the largest reads in muscle-wasting models (mdx mice, Duchenne models, aged sarcopenia models). The clinical promise was that a once-monthly or once-every-other-week injection could deliver myostatin blockade strong enough to reverse muscle wasting in disease populations without the genetic-knockout-style "double muscling" risks of pure myostatin antibodies. The problem the Phase 2 trials surfaced is that ActRIIB also binds BMP9 and BMP10, which regulate vascular endothelial integrity. Trapping those ligands alongside myostatin is the most-cited mechanistic explanation for the bleeding/vascular leak side effects that ended the program.
Typical dose ranges by experience level - educational reference. Message us and we tailor it to you.
First-cycle users should bank baseline observations before injection: resting heart rate, blood pressure, any history of gum bleeding when brushing, frequency of nosebleeds, baseline bruising. Any meaningful increase in any of these signals during the cycle is a stop sign, not a "push through" signal. Read body composition at week 4. Expect modest pumps and recovery improvement at this dose, not dramatic recomposition. Most of the published data is at 10-100x these doses, so the beginner protocol is genuinely experimental.
This is the working dose band for self-experimenters who are tracking lean mass and grip strength changes. Pair with a hypertrophy training block (3-5 lifting sessions per week) and a slight caloric surplus or maintenance. Read body composition at week 6. Watch carefully for telangiectasias (small spider veins, often on cheeks or chest), unusual bruising, or any nosebleed at all. These are the early warnings the Phase 2 trials surfaced.
Even at advanced community doses, this is a high-risk compound. The bleeding/vascular signals were dose-dependent in the trials, so going higher carries real, documented risk. Most experienced researchers cycle conservatively because the long half-life (~10-15 days) means a dose given today is still active 3-4 weeks later, and stacking weekly doses produces accumulation. Discontinue at the first sign of nosebleed, gum bleeding, unusual bruising, or new telangiectasias.
Straight talk - what people actually report, and what the studies measured.
Peer-reviewed studies and clinical guidelines - tap any to read the source.
single-dose lean mass increase, biomarker confirmation, first human safety signals
Read study ↗PubMedCampbell et al, Muscle Nerve 2017 - Phase 2 trial of ACE-031 in Duchenne muscular dystrophyfull Phase 2 outcome data, epistaxis and gum bleeding signals, vascular leak discussion, trial termination rationale
Read study ↗PubMedCadena et al, Sci Rep 2019 - administration of myostatin inhibitors and vascular adverse effectsmechanism discussion of BMP9/BMP10 sequestration and vascular leak
Read study ↗PubMedLee, Annu Rev Physiol 2023 - Targeting myostatin/activin pathway for sarcopenia and muscle wastingpathway biology, comparison of ACE-031 vs follistatin vs anti-myostatin antibodies, why the soluble decoy approach is mechanistically attractive but pharmacologically tricky
Read study ↗PubMedBogdanovich et al, Nature 2002 - Functional improvement of dystrophic muscle by myostatin blockadefoundational preclinical work in mdx mice that drove the ACE-031 program
Read study ↗Clinical guidelinesAcceleron Pharma Phase 2 termination press release (archived)](https://www.fiercebiotech.com/biotech/acceleron-shutters-program-after-second-trial-halt) - official program discontinuation, vascular and bleeding rationale
Read study ↗Aggregated sentiment from public forums & socials - real-world reports, not individual endorsements.
Bodybuilding/peptide forum reports at low doses (1-3 mg/week): muscle fullness, pump quality improvement, modest scale weight (2-5 lb over 4 weeks) - small population, not a robust signal
Nosebleeds: reported even at sub-clinical community doses by a meaningful minority of users - the dose-dependent threshold appears lower than some hoped
Gum bleeding when brushing: reported, often the first sign and the most common "I stopped the cycle" trigger
Easy bruising: reported, sometimes only noticed retrospectively
Telangiectasias: small spider veins on cheeks reported by a handful of advanced users, generally faded after discontinuation (not always)
Headaches: moderate frequency, often associated with dose increase
Route: SubQ injection (most community use); IM is the published trial route, both function
Injection site: abdomen or outer thigh for SubQ, rotate sites; deltoid/glute for IM if running the trial-style protocol
Storage: refrigerated, ~14 days after reconstitution (fusion proteins are less stable post-recon than small peptides). Pre-recon vials: refrigerated, freezer for long storage.
Notes: This is a large recombinant fusion protein, not a small peptide. Handle gently, do not shake the vial (swirl), inject slowly, use fresh insulin syringe per draw. The published Phase 2 dosing was 1-3 mg/kg IV or SubQ every 2-4 weeks (so 70-210 mg per dose for an 70 kg adult), which is roughly 50-100x what community researchers actually run. Self-experimenters dose far lower because (a) supply is gated by tiny 1 mg vials, not gram-scale clinical material, and (b) the safety signals at full clinical doses are well documented and most researchers explicitly want to stay below the bleeding threshold. The half-life of ~10-15 days means weekly or biweekly dosing is sufficient at any reasonable dose.