Update
ACE-031 was stopped in a trial in children. It is still on sale.
A myostatin trap that reached phase 2 in Duchenne muscular dystrophy, halted after the second dosing regimen for nosebleeds and burst capillaries. Seven of the vendors we track list it.
ACE-031 is not a peptide. It is a fusion protein — the business end of the activin receptor type IIB stitched to the tail of a human antibody — and it works as a decoy, intercepting myostatin before it reaches muscle. Blocking myostatin is a genuinely good idea with a long history, and Acceleron Pharma and Shire took this molecule further than most: into a randomised, placebo-controlled phase 2 trial in ambulatory boys with Duchenne muscular dystrophy.
That trial was stopped after the second dosing regimen. Not for lack of effect. Participants developed epistaxis — nosebleeds — and telangiectasias, the small dilated vessels you can see through skin. Both resolved when dosing stopped, and both indicated the drug was doing something to blood vessels that nobody had designed it to do. Development was halted in 2011 and discontinued permanently in 2013.
The likely reason is the part worth understanding before buying any myostatin inhibitor. The trap is not selective. The same receptor binds activin A and GDF-11 alongside myostatin, and ACE-031 soaks up all of them. Activin signalling has a role in vascular biology, which is a reasonable account of why a muscle drug produced a bleeding problem.
The efficacy findings, for completeness, were trends. Six-minute walk distance held up better than placebo, lean mass and bone mineral density rose, fat mass fell — and none of it reached statistical significance, because the trial stopped before it could.
So the position is unusually well defined for a research chemical. This is not a compound nobody has studied. It is one a pharmaceutical company studied properly, in children with a fatal muscle-wasting disease, and stopped giving them because of what it did to their blood vessels — with monitoring in place and a stopping rule they used. Seven of the vendors we track sell it today, with neither.
It has a profile here now, because people are buying it and a page saying what happened is more use than no page. Two practical notes on it: the half-life is measured in weeks, so an unwanted effect cannot be stopped quickly, and it is a recombinant glycoprotein rather than a synthetic peptide — whether a given vial is correctly folded is not something a buyer can determine, and an incorrectly folded protein is a different molecule.
Compounds this concerns
This page is educational. It describes what published research reports, not what you should do. Peptides discussed here are largely not approved for human use, and nothing on Bioalmanac is medical advice.