§ 01 Overview
Overview
Fully human mAb against activin type-II receptors. Failed sarcopenia and sIBM endpoints; now developed by Lilly for obesity in combination with tirzepatide (BELIEVE trial).
Failed primary endpoints in sarcopenia and sIBM. BELIEVE Phase 2 tests combination with tirzepatide.
§ 02 Mechanism
Mechanism of action
Bimagrumab blocks ActRIIA/B to prevent myostatin, activin A, and GDF-11 signaling. It drives muscle hypertrophy with simultaneous fat loss, which makes it interesting as an obesity adjunct that preserves lean mass while GLP-1 class drives caloric deficit.
- 01Increases lean mass + decreases fat mass simultaneously
- 02Attractive for muscle-preserving obesity therapy
§ 03 Dosing
Dosing protocol
Standard Protocol
- Dose Range
- 10 mg/kg IV (trial)
- Route
- Other
- Frequency
- Monthly (trial)
§ 04 Evidence
Evidence & research
Failed primary endpoints in sarcopenia and sIBM. BELIEVE Phase 2 tests combination with tirzepatide.
FDA Status
Not FDA-approved. In development for obesity in combination.
§ 06 News
In the news
8 articles from the last 12 months · updates hourly
Harbour posts preclinical data on would-be rival to Eli Lilly’s $1.9B obesity bet - European Biotechnology Magazine
Harbour posts preclinical data on would-be rival to Eli Lilly’s $1.9B obesity bet European Biotechnology Magazine
The GLP-1 Drug Combo That May Preserve Lean Muscle During Weight Loss Treatment - Verywell Health
The GLP-1 Drug Combo That May Preserve Lean Muscle During Weight Loss Treatment Verywell Health
How Bimagrumab and Semaglutide Deliver Fat Loss While Preserving Lean Mass - Docwire News
How Bimagrumab and Semaglutide Deliver Fat Loss While Preserving Lean Mass Docwire News
Bimagrumab-Semaglutide Combination Achieves Significant Weight Loss While Preserving Muscle Mass - Pharmacy Times
Bimagrumab-Semaglutide Combination Achieves Significant Weight Loss While Preserving Muscle Mass Pharmacy Times
Results Show Bimagrumab With Semaglutide Achieve Substantial Weight Reduction - Drug Topics
Results Show Bimagrumab With Semaglutide Achieve Substantial Weight Reduction Drug Topics
This New Drug Combo Beats GLP-1s Alone, Without One of the Biggest Side Effects - inc.com
This New Drug Combo Beats GLP-1s Alone, Without One of the Biggest Side Effects inc.com
Trial suggests GLP-1 combo therapy cuts fat while preserving muscle in obesity - Medical Xpress
Trial suggests GLP-1 combo therapy cuts fat while preserving muscle in obesity Medical Xpress
‘Musclezempic’ Could Be the Future of Weight Loss - Gizmodo
‘Musclezempic’ Could Be the Future of Weight Loss Gizmodo
§ 07 Sourcing
Sourcing & supply
Regulatory status
Investigational, no compounding path
Currently in active clinical trials. No compounding pathway. No brand product. The only US channels are RUO vendors that the FDA has targeted with warning letters. Assume any sourcing carries significant regulatory and quality risk.
No suppliers in our directory currently stock this compound. For investigational or research-only compounds, legitimate channels may not exist outside clinical trials.
Browse full supplier directory§ 09 Safety
Safety & side effects
Side effects
- 01Muscle spasms
- 02Diarrhea
- 03Injection site reactions
Contraindications
None specified.
§ 10 Questions
Bimagrumab FAQ
- What is Bimagrumab?
- Fully human mAb against activin type-II receptors. Failed sarcopenia and sIBM endpoints; now developed by Lilly for obesity in combination with tirzepatide (BELIEVE trial). Bimagrumab blocks ActRIIA/B to prevent myostatin, activin A, and GDF-11 signaling. It drives muscle hypertrophy with simultaneous fat loss, which makes it interesting as an obesity adjunct that preserves lean mass while GLP-1 class drives caloric deficit.
- What is Bimagrumab used for?
- Reported uses include increases lean mass + decreases fat mass simultaneously and attractive for muscle-preserving obesity therapy. Evidence strength is rated Clinical — see the evidence section for detail.
- How is Bimagrumab dosed?
- Commonly referenced dosing is 10 mg/kg IV (trial), typically monthly (trial), administered Other. This is educational reference only; consult a licensed clinician before use.
- What are the side effects of Bimagrumab?
- Commonly reported side effects include muscle spasms, diarrhea, and injection site reactions. This list is not exhaustive.
- Is Bimagrumab legal?
- Currently in active clinical trials. No compounding pathway. No brand product. The only US channels are RUO vendors that the FDA has targeted with warning letters. Assume any sourcing carries significant regulatory and quality risk. FDA status: Not FDA-approved. In development for obesity in combination..
§ 11 References
Selected references
- 01
Rooks sarcopenia trial
PMID: 28653345 (NCT02333331)
- 02
sIBM long-term
PMID: 32737152
- 03
BELIEVE — tirzepatide combo
NCT05616013