ACE-031 is a myostatin/activin trap. GDF-8 is a growth factor.
| Comparison | ACE-031 (Ramatercept) ramatercept · ACE-031 | GDF-8 (Myostatin) myostatin · growth differentiation factor 8 |
|---|---|---|
| How it works | How it works ACE-031 is a decoy: a piece of the receptor that myostatin binds to, floating free in the blood so myostatin binds it instead of muscle. | How it works Getting this one backwards is easy and it is worth being clear. |
| What it is | An experimental muscle-builder whose development was paused over side effects. | The protein that limits muscle growth, which is the opposite of what most buyers want. |
| Status | Research only | Research only |
| Typical dose | — | — |
| How often | Cycled | Varies |
| Stays active | About 10 to 15 days | Nothing published in humans |
| Dose comes from | No established range | No established range |
| Cycled? | No schedule exists. Development was halted Clinical trial protocol | No established pattern No established range |
| What it does | ||
| Drug class | Myostatin/activin trap | Growth factor |
| Used for | An experimental muscle-builder that soaks up the natural brakes on muscle, producing big gains in studies. | Used as a research reagent. Sold by peptide vendors, where it is frequently confused with the compounds designed to block it. |
| Receptors hit | — | — |
| Numbers | ||
| Full dose line | Trial doses | Research only |
| Why that cycle | Stopped in 2013 during phase 2 in Duchenne muscular dystrophy after nosebleeds and small vessel changes appeared. Whatever schedules circulate for it, none survived the trials. | No published human study establishes a schedule. |
| Weight / effect | Not measured in a trial | Not measured in a trial |
| Chain length | Not disclosed | Not disclosed |
| Common vial | 1 mg | 1 mg |
| Before you start | ||
| Route | Under the skin (subcutaneous) | Under the skin (subcutaneous) |
| Do not use if | Any bleeding disorder, or a personal or family history of unusual bleeding Development was halted, so it is not available and nobody is assessing anyone for it | Any non-laboratory use Pregnancy or breastfeeding |
What separates them
Proof behind the dose. Every dose here comes from community practice. Not one is backed by a published human study, which is worth knowing before you read the numbers as if they were equivalent.
What doesn't differ: They are both taken the same way (under the skin) and aimed at the same thing (muscle growth). Neither has a measured effect size from a published trial, so there is no number to rank them on.
What people actually report
ACE-031 (Ramatercept)
- Its development was paused after side effects like nosebleeds and gum bleeding showed up in trials.
- Unusual nosebleeds
- Bleeding gums
GDF-8 (Myostatin)
- No human safety data exists for administering myostatin.
- No reason exists to administer it, since its biological role is to limit muscle.
- Any use at all, since this is a research reagent rather than a compound with a human application
Side effects are what users and trials report most often, not a complete list. Anything sudden, spreading, or breathing-related is an emergency regardless of which compound caused it.
People also compare
This comparison does not cover cost, long-term safety, or how you personally will respond. Effect figures come from separate trials in different populations and are not always directly comparable to each other. Nothing here is medical advice or a recommendation to use any of these. Talk to a clinician about your own situation.