What is ACE-031?
ACE-031 (ramatercept) is a fusion protein that mimics part of the activin receptor IIB and so traps myostatin and related messengers before they take effect. Myostatin is the muscle's natural growth brake, ACE-031 releases that brake.
Important: ACE-031 is not a small peptide but a large protein that was dosed in mg per kilogram of body weight. Clinical development was stopped due to side effects.
How it works
Normally myostatin brakes muscle growth via the ActRIIB receptor. ACE-031 acts like a trap: it catches myostatin and related activins so the braking signal does not reach the receptor. The result in studies was a gain in lean mass.
The catch: the ActRIIB receptor controls not only muscle but also blood vessels, hence the problematic side effects.
What you need
- The ACE-031 vial (lyophilized powder).
- Bacteriostatic water, insulin syringes, alcohol swabs.
Reconstitution
Use the calculator above for concentration and volume. But note: in the studies ACE-031 was dosed in mg per kilogram of body weight, in far higher amounts than small vials provide. For research use there is no established, safe protocol.
Dosing
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Injection
Subcutaneous in the studies. Lacking an established protocol and given the safety record, particular restraint is warranted here.
What the research shows
A phase 1 study (Attie, 2013) showed a dose-dependent rise in lean mass in healthy women, so ACE-031 works. But a study in boys with Duchenne muscular dystrophy (Campbell, 2017) was stopped early after side effects like nosebleeds, gum bleeding and dilated blood vessels appeared.
These vascular side effects are why ACE-031 never reached approval. That should be known before even considering it.
Side effects
- Nosebleeds and gum bleeding.
- Dilated small blood vessels (telangiectasia) on the skin.
- These vascular effects led to the stop of clinical development.
Practice
- Development was stopped for safety reasons, the clearest signal there is.
- No established, safe dosing protocol.
- Banned in official competition.
Storage
Before mixing the powder is robust, normal room temperature (around 20 to 25 degrees) is fine, ideally kept in the dark. After mixing, keep in the fridge (2 to 8 degrees), do not freeze. It stays good there for at least 8 to 10 weeks with barely any loss of potency, in practice considerably longer. Swirl or shake to mix, both are fine.