ACE-031 calculator
An investigational myostatin-inhibiting protein developed for muscular dystrophy. Development was halted over safety signals.
Also known as: Activin receptor type IIB, ActRIIB-Fc
FDA status — not an approved drug Not FDA-approved for any use. ACE-031 is an investigational protein whose clinical development was discontinued after safety signals in trials.
This draw does not fit the selected syringe.600 units exceeds the 100-unit barrel. Choose a larger syringe, use less bacteriostatic water, or split the dose.
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What ACE-031 is
ACE-031 is an investigational soluble form of the activin type IIB receptor, developed to treat Duchenne muscular dystrophy by blocking myostatin. It produced muscle growth in studies, but clinical development was halted after safety signals including minor bleeding and vascular changes. It is a prominent cautionary case in the myostatin-inhibition field.
Research depth: 2/5 Reached human trials but was discontinued over safety signals; a cautionary case. Human trials: Trials discontinued. This measures how much has been studied — counting animal and laboratory work — not whether it works for you.
How ACE-031 works
It acts as a decoy receptor, binding and neutralizing myostatin and related TGF-beta-family proteins before they can reach their receptors on muscle. Blocking this signaling releases the brake on muscle growth. The off-target effects on blood vessels that emerged in trials are what ended its development.
ACE-031 side effects
Commonly reported
- Minor bleeding — nosebleeds and gum bleeding reported in trials
- Dilated small blood vessels in the skin (telangiectasia)
- Headache
Serious — seek medical care
- Development halted over bleeding and vascular safety signals
- Myostatin-pathway blockade may have unstudied effects on the heart and blood vessels
- No approved form; products are unregulated
This list is not exhaustive. Report anything unexpected to the clinician who prescribed it. If you have severe abdominal pain, trouble breathing, or signs of an allergic reaction, seek care the same day. See also our guide to peptide side effects by class.
A worked example
A 1 mg vial reconstituted with 2 mL of bacteriostatic water gives 0.5 mg/mL. A 3000 mcg dose is then 6 mL — about 600 units on a 100-unit insulin syringe, giving roughly 0 doses per vial before accounting for residual volume left in the vial and syringe.
Prefer paper? Download the printable ACE-031 dosing chart (PDF) — every vial size and water volume in syringe units, with the same review byline as this page. All charts →
Commonly cited dose range
Figures circulating for ACE-031 run from 1000 mcg to 10000 mcg. No established dosing exists — development was discontinued. Figures shown are reference points from trial discussion in micrograms. There is no approved or established dose.
Read this as reference information, not instruction. These numbers describe what is commonly discussed, not what is right for any individual. Dose, frequency, and whether to use ACE-031 at all are decisions for a licensed clinician who knows your history.
Common questions
Why was ACE-031 development stopped?
Clinical trials in muscular dystrophy were halted after reports of adverse effects including minor bleeding (nosebleeds, gum bleeding) and dilated blood vessels in the skin. The program was discontinued.
How does ACE-031 build muscle?
It acts as a decoy receptor for myostatin and related proteins, soaking them up so they cannot signal muscle to stop growing. Blocking myostatin releases the brake on muscle growth.