Metabolic & endocrine
An investigational antibody that inhibits myostatin activation, with a peer-reviewed Phase 2 trial showing less DXA-measured lean-mass loss during tirzepatide treatment, but no proven functional outcome in obesity.
Evidence passport
A one-screen evidence identity for this compound. These fields describe research maturity, confidence and legal status. They are not a safety guarantee, efficacy percentage or recommendation.
Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.
The 0-100 values rate the strength and maturity of evidence, not how effective or safe the compound is.
Routes recorded
Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.
Evidence for the assessed benefit
Controlled Phase 2 evidence supports less DXA-measured lean-mass loss during tirzepatide-associated weight loss over 24 weeks. DXA lean mass is not synonymous with skeletal muscle, and the trial does not establish better strength, mobility, frailty or long-term outcomes.
Human research context: 102 adults with overweight or obesity receiving tirzepatide in EMBRAZE.
Research maturity, benefit evidence, safety and approval are different questions.
Every number here rates the evidence, not the compound. They are editorial 0-100 strength ratings, not percentages, and not a rating out of five stars.
None of these ratings is medical advice, a safety guarantee, or a recommendation to use anything. How we grade evidence.
How far human research has progressed: Completed randomized, double-blind, placebo-controlled Phase 2 (EMBRAZE) in obesity; peer reviewed in Nature Medicine, 8 June 2026
Studied / approved routes
Studied as an intravenous infusion in clinical trials. This describes the trial route only, not advice for use.
Route availability is not evidence of efficacy, and evidence from one route does not transfer to another. The Registry never provides dosing or sourcing information.
Discovery
Preclinical
Phase I
Phase II
Furthest established stage
Phase III
Approved
Proof-of-concept Phase 2 completed in obesity.
Last documented development: 8 June 2026 — EMBRAZE Phase 2 published in Nature Medicine
A fully human monoclonal antibody that selectively binds the precursor forms of myostatin and inhibits their activation, without reported activity toward other TGFβ-family members.
In EMBRAZE (randomized, double-blind, placebo-controlled; 102 adults on tirzepatide), apitegromab resulted in a least-squares mean of 1.9 kg (80% CI 1.2–2.7) less DXA-measured lean-mass loss than placebo at week 24 (P = 0.001), with similar total weight loss; lean-mass loss was 1.6 kg versus 3.5 kg, reported as 54.9% relative retention. This is a body-composition endpoint, not proof of better physical function in obesity.
Useful next reads based on this compound — not recommendations.
CBL-514 evidence profile
An investigational localized fat-reduction small-molecule injection, studied for abdominal subcutaneous fat reduction rather than whole-body obesity treatment. Not a peptide.
Compare Apitegromab vs CBL-514 evidence
Same questions, same fields, side by side — including how much human evidence exists.
Safety Centre
What approved, investigational and unapproved actually mean for documented human safety.
Research Desk
How to read animal, early-phase and controlled human studies without over-reading them.
Animal and cell findings are Level 1–2 evidence.
This section covers questions raised by how the compound works in the body, plus anything regulators and trial teams keep an eye on. It is not a statement that this compound causes cancer — for most compounds here, no human data exist in either direction.
Monitored in trials; not demonstrated in humans
Regulatory decisions apply to specific jurisdictions, products, formulations and indications. An approval elsewhere is not automatically an approval in your country.
Check the regulatory note and linked primary sources for jurisdiction-specific details.
Not approved for any indication in our record. Obesity/body-composition use is investigational.
Completed, adequately informative controlled human trials supporting a specified outcome; replication and longer-term safety may remain uncertain.
Source transparency
A provenance snapshot of this profile. Counts show what kinds of sources are cited, not how much scientific weight each source deserves.
Review provenance
Registry editorial review: Colin Jackson-White, creator and editor, who is not a doctor or clinician. External specialist review is credited only when a named reviewer has completed a review of this exact profile.
Literature-discovery and AI tools may help locate or challenge candidate evidence, but they are not counted as evidence sources here. Registry judgements are tied to the underlying papers, trial records, regulator documents and official study records.
Source hierarchy: regulatory documents and trial registries first, peer-reviewed work next, sponsor material flagged as non-independent. We never use supplier or clinic marketing as evidence, and where a verified source has not yet been curated we say so rather than inventing one.
These entries record changes to our assessment of the published evidence — not changes to the compound itself.