Myostatin / activin-pathway inhibitors (non-bimagrumab)
Muscle & Strength · Myostatin/activin blockade
Tier C
High-risk evidence profile
Bottom line
Read Off Label grades Myostatin / activin-pathway inhibitors (non-bimagrumab) as C (4.9/10) based on moderate evidence, med benefit magnitude, and a med-high-risk safety profile.
Its high-risk evidence profile reflects a Safety score of 3.5/10; reported benefits and harms can differ by indication, dose, route, duration, and population.
WADA coverage: activin A-neutralizing antibodies, activin receptor IIB competitors, decoy activin receptors, ACE-031, anti-activin receptor IIB antibodies, myostatin inhibitors, agents reducing or ablating myostatin expression, myostatin-binding proteins, follistatin, myostatin propeptide, myostatin- or precursor-neutralizing antibodies, apitegromab, domagrozumab, landogrozumab and stamulumab.
Studied, labeled, or reported-use context: Trial dosing varies widely by biologic; no approved enhancement dose — Investigational/Rx biologics depending program; WADA S4 prohibited; not individualized guidance.
What the evidence says
WADA coverage: activin A-neutralizing antibodies, activin receptor IIB competitors, decoy activin receptors, ACE-031, anti-activin receptor IIB antibodies, myostatin inhibitors, agents reducing or ablating myostatin expression, myostatin-binding proteins, follistatin, myostatin propeptide, myostatin- or precursor-neutralizing antibodies, apitegromab, domagrozumab, landogrozumab and stamulumab. Bimagrumab remains its own row. Additional WADA alias coverage: luspatercept and sotatercept are TGF-beta/activin-family ligand traps listed by WADA under related growth-factor modulation. Jul 2026: Unlimited Biotechnology registered CALM-AF-AI (NCT07443826), a first-in-class Phase 1/2a trial combining AAV9-follistatin gene therapy with a VEGF plasmid for age-related muscle decline -- notable because it is the first clinical trial to pair these two gene therapies. Important caveat: the trial runs at a private clinic in Prospera, Roatan (Honduras), a jurisdiction with minimal regulatory oversight; the company's own CEO has acknowledged the data are unlikely to be accepted by the FDA or EMA, and the program has drawn medical-tourism criticism. No efficacy or safety data yet -- tracked here, not promoted to a standalone row or the public watchlist given the regulatory caveats.
Mechanism
Blocking myostatin or activin receptor signaling can increase lean mass in some clinical contexts; functional improvements are much less consistent than muscle-volume changes.
Studied, labeled, or reported dose & route
Trial dosing varies widely by biologic; no approved enhancement dose
This records doses and routes described in studies, approved labeling, clinical practice, or documented use. It is not individualized guidance and does not establish safety; context changes with indication, formulation, health history, monitoring, and other medicines.
Citations
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Common questions
- What does the evidence show about Myostatin / activin-pathway inhibitors (non-bimagrumab)'s effects?
- Read Off Label rates the evidence for Myostatin / activin-pathway inhibitors (non-bimagrumab) as Moderate and the benefit magnitude as med, producing an overall grade of C (4.9/10). WADA coverage: activin A-neutralizing antibodies, activin receptor IIB competitors, decoy activin receptors, ACE-031, anti-activin receptor IIB antibodies, myostatin inhibitors, agents reducing or ablating myostatin expression, myostatin-binding proteins, follistatin, myostatin propeptide, myostatin- or precursor-neutralizing antibodies, apitegromab, domagrozumab, landogrozumab and stamulumab.
- What safety findings are reported for Myostatin / activin-pathway inhibitors (non-bimagrumab)?
- Myostatin / activin-pathway inhibitors (non-bimagrumab) has a med-high risk profile in the database. Med-High (reproductive/endocrine-axis effects, vascular/tissue-remodeling uncertainty, injection biologic risks) Legal status: Investigational/Rx biologics depending program; WADA S4 prohibited.
- What does the low Safety score for Myostatin / activin-pathway inhibitors (non-bimagrumab) represent?
- The Safety score is 3.5/10. It records the substantial harms described for one or more use contexts; the Benefit score, indication, dose, route, duration, population, and legal status remain separate parts of the evidence profile.
- What doses or routes are reported for Myostatin / activin-pathway inhibitors (non-bimagrumab)?
- Trial dosing varies widely by biologic; no approved enhancement dose This is context from studies, approved labeling, clinical practice, or documented use; it is not individualized guidance and does not establish safety.
- How does Myostatin / activin-pathway inhibitors (non-bimagrumab) work?
- Blocking myostatin or activin receptor signaling can increase lean mass in some clinical contexts; functional improvements are much less consistent than muscle-volume changes.
This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.