ACE-031 is a myostatin/activin trap. FLGR242 is a claimed follistatin construct, identity unverified.
| Comparison | ACE-031 (Ramatercept) ramatercept · ACE-031 | FLGR242 Follistatin FLGR242 |
|---|---|---|
| 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 The idea behind FLGR242 is straightforward. Whether the vial contains it is the open question. |
| What it is | An experimental muscle-builder whose development was paused over side effects. | Sold as an upgraded follistatin. Nobody outside the sellers has said what is in the vial. |
| Status | Research only | Research only |
| Typical dose | — | — |
| How often | Cycled | No established schedule |
| Stays active | About 10 to 15 days | No published figure for this construct |
| Dose comes from | No established range | No established range |
| Cycled? | No schedule exists. Development was halted Clinical trial protocol | No established schedule No established range |
| What it does | ||
| Drug class | Myostatin/activin trap | Claimed follistatin construct, identity unverified |
| Used for | An experimental muscle-builder that soaks up the natural brakes on muscle, producing big gains in studies. | A vendor-introduced follistatin product sold for muscle growth. Its composition rests on seller copy alone. |
| Receptors hit | — | — |
| Numbers | ||
| Full dose line | Trial doses | No established dose |
| 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. | Nothing has been studied, so nothing can be recommended. Schedules quoted for it are borrowed from follistatin. |
| Weight / effect | Not measured in a trial | Not measured in a trial |
| Chain length | Not disclosed | Not disclosed |
| Common vial | 1 mg | 10 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 active cancer, since myostatin and activin signalling interact with tumour biology Existing heart disease, because myostatin is expressed in cardiac muscle Pregnancy and breastfeeding Banned in drug-tested sport |
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
FLGR242
- No independent certificate of analysis names what is in the vial. Every composition claim traces to seller copy.
- Sellers contradict each other on the most basic point: some describe a recombinant glycoprotein of roughly 40 kDa, one describes a synthetic peptide analogue. Those are different products.
- Myostatin inhibition has never been shown safe in healthy people, and blocking it affects heart and tendon tissue as well as skeletal muscle.
- Banned in drug-tested sport as a myostatin inhibitor.
- Shortness of breath, chest pain, or swelling in the legs
- Tendon pain, or a joint giving way, since muscle can outgrow the tendon that carries it
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.