Peptide reference → Athletic performance → ACE-031 (Ramatercept)

ACE-031 (Ramatercept)

Research use

Myostatin trap protein (experimental) · also known as Ramatercept

Last updated 29 October 2026

ACE-031, also called ramatercept, is an experimental protein designed to trap myostatin and related signals so that muscle can grow. Its trials were stopped over safety concerns, and it has no UK marketing authorisation. It is prohibited in sport.

Key points

ACE-031 is a laboratory made protein that acts as a decoy, soaking up myostatin and related growth limiting signals.
In an early trial a single dose raised lean mass, but a trial in boys with muscular dystrophy was stopped over bleeding related side effects.
Its development was ended over a decade ago, and products sold online often do not even contain it.
It has no UK marketing authorisation, and it is named on the WADA Prohibited List.

Quick facts

What it is: Experimental myostatin trap protein (ramatercept)
Studied for: Muscle growth; muscular dystrophy (trials halted)
UK status: Not a licensed medicine; development ended
Safety: Trials stopped over bleeding related effects
In sport: Named on the WADA Prohibited List

How it works

Myostatin limits muscle growth. ACE-031 is built from part of a receptor that myostatin binds to, so it works as a trap, mopping up myostatin before it can act. In theory that allows more muscle to build, which is what the early trial suggested.

What the evidence shows

Early trials were small. A single dose raised lean mass in healthy volunteers, but a trial in boys with Duchenne muscular dystrophy was halted because of nosebleeds and small dilated blood vessels in the skin, with no clear benefit to walking. The programme was then ended.

What it does not settle

Benefit in any disease was not established before trials stopped.
Long term safety, and a safe dose, are not known.
Testing has found that black market products often contain no ACE-031 at all.

Side effects

Common

In trials, nosebleeds, gum bleeding, small dilated blood vessels in the skin, injection site redness and headache were reported.

Less common but serious

The bleeding and blood vessel effects were serious enough to stop its development.
Because there is no licensed product, the dose, purity and contents of material bought online cannot be verified, and many products contain nothing active.

Report any suspected side effect through the MHRA Yellow Card scheme.

UK legal status and access

ACE-031 has no UK marketing authorisation, so it is not a licensed medicine and is not offered by registered clinics or pharmacies. It is sold online as a research chemical, often not containing what the label claims.

Common questions

What is ACE-031?

An experimental protein that traps myostatin to allow muscle growth. Its trials were stopped over bleeding related side effects.

Is it allowed in sport?

No. Decoy myostatin traps such as ACE-031 are named on the WADA Prohibited List.

The licensed route

There is no licensed ACE-031. For muscle, strength or recovery, a registered clinician, physiotherapist or qualified coach can advise on safe, evidence based approaches.

Factual reference only, not medical advice. We give no dosing for unlicensed compounds.

← All peptides