ACVR2B-Fc · Activin Receptor Blocker
Activin receptor blocker — myostatin and GDF-11 inhibition.
FDA
Research Only
WADA
Banned
HALF-LIFE
~2 weeks
ROUTE
SubQ injection
SCHEDULE
Once every 1–2 weeks
In Plain English
Activin receptor blocker — myostatin and GDF-11 inhibition.
Status & Legality
NATTY?
Not NattyWADA banned substance. Tested athletes will fail.
FDA
Research OnlyFor research purposes only. Not FDA approved.
WADA
BannedOn WADA prohibited list. Use disqualifies in tested sports.
COMPOUNDING
Not from pharmaciesNot available from licensed compounding pharmacies.
PRESCRIBED
Not prescribedNot prescribed in conventional medicine.
ROUTE
SubQ injectionAdministration via subq injection.
Muscle mass increase
Myostatin inhibition
Muscular dystrophy research
Performance
ACE-031 is a fusion protein acting as a soluble activin receptor type IIB decoy. It traps multiple myostatin-pathway ligands (myostatin, GDF-11, activin A), providing broader anabolic effects than follistatin alone. Developed for muscular dystrophy, clinical trials were halted due to vascular side effects at high doses.
Telangiectasias (nose bleeds, skin vessels)
Gingival bleeding
Significant muscle soreness
Joint pain
Not monitoring for telangiectasias — nosebleeds and small skin vessel dilations were documented in clinical trials; monitor actively throughout use
Exceeding 1 mg/kg without medical oversight — the adverse vascular events in trials occurred primarily at higher doses
Combining with Follistatin at full doses of each — dual myostatin pathway blockade at full doses is extremely potent; experienced guidance is required
Anabolic steroids — compounded vascular and anabolic effects; risk of adverse events increases substantially
Anticoagulants — telangiectasias increase bleeding risk; anticoagulants compound this significantly
Follistatin — can be combined but requires conservative doses of each and active monitoring
ACE-031 is the most potent myostatin-blocking compound available but also the most risk-laden. The clinical trial halt due to vascular side effects is a real signal — not marketing caution. Meaningful at 1 mg/kg every 2 weeks, but active monitoring of skin vessels and nose bleeds throughout is non-negotiable, not optional.
Stats
Sources & Studies
Wagner KR. et al., Neuromuscul Disord, 2013