A single injection of a targeted antibody-siRNA conjugate in CD-1 lean mice increased leg muscle size by 14.8% and maintained muscle mass for more than five weeks without affecting myostatin levels elsewhere in the body.
See the scientific wording
In CD-1 lean mice, a single administration of an antibody-siRNA conjugate targeting myostatin increases leg area by 14.8% and preserves skeletal muscle mass for over five weeks without systemic myostatin inhibition.
Correlational — new studies may shift this
ObservationalOne low-scoring study links this claim to the outcome, but causation is not established.
What the research says
1 study reviewedSupporting (1)
2185-LB: Antibody-siRNA Conjugate Targeting Myostatin Preserves Muscle Mass during GLP-1R Agonism
Case-Control StudyAnimal
A single shot of a special targeted drug made healthy mice’s legs 14.8% bigger, and the muscle stayed bigger for over five weeks — without affecting other parts of the body. This proves the drug works locally where it’s supposed to.
Contradicting (0)
No contradicting studies found yet
That doesn't mean it's settled — it just means no study has tested the opposite.
Quality-weighted scoring: we follow the GRADE framework — each study is rated High, Moderate, Low, or Very Low based on study design, methodology rigor, and risk of bias. A single high-quality RCT can outweigh several weaker observational studies.
Scores reflect study quality, not just count.
A special drug binds to a receptor found only on muscle cells, gets pulled inside, and turns off a gene that normally stops muscle growth. This lets muscle fibers get bigger and stay bigger for weeks without affecting other parts of the body.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting study
How Fit Body Science checks a claim
- 1
We isolate the claim
Health advice from videos, articles and studies is broken down into single, testable claims.
- 2
We find the research
Each claim is matched against peer-reviewed studies, with every source cited by DOI.
- 3
We grade the evidence
Studies are scored on methodology, statistical rigor, transparency and publication quality.
The fitness and health internet is full of confident claims. We check them against real research.
Every claim on this site is traced back to peer-reviewed studies, scored on methodology and reporting quality, and given a verdict you can audit yourself — sources, DOIs and all.
- Full evidence breakdown and mechanism chains
- Ask our AI anything about a claim or its studies
- Get notified when new research changes a verdict
A single injection of a targeted antibody-siRNA conjugate in CD-1 lean mice increased leg muscle size by 14.8% and maintained muscle mass for more than five weeks without affecting myostatin levels elsewhere in the body.
Mechanism
1 studyA drug designed to target only muscle cells turns off a gene that limits muscle growth. This lets muscles grow larger and stay larger for weeks, without affecting any other part of the body.
A special drug binds to a receptor found only on muscle cells, gets pulled inside, and turns off a gene that normally stops muscle growth. This lets muscle fibers get bigger and stay bigger for weeks without affecting other parts of the body.
A transferrin receptor 1-targeting antibody binds to transferrin receptor 1 on the surface of skeletal muscle cells
The antibody-siRNA conjugate is internalized into muscle cells through receptor-mediated endocytosis
The siRNA component is processed by the RNA-induced silencing complex and degrades myostatin mRNA
Myostatin protein levels decrease, removing inhibition of the SMAD2/3 signaling pathway
De-repression of muscle growth pathways increases protein synthesis and myofiber hypertrophy
Silenced myostatin mRNA and sustained siRNA presence maintain low myostatin levels for over five weeks
Evidence from Studies
Supporting (1)
Community contributions welcome
A single shot of a special targeted drug made healthy mice’s legs 14.8% bigger, and the muscle stayed bigger for over five weeks — without affecting other parts of the body. This proves the drug works locally where it’s supposed to.
Contradicting (0)
Community contributions welcome
Score Breakdown
No multi-axis breakdown available yet. The overall Pro / Against score above is the best signal.
- No clinical evidence is available; the score reflects mechanistic plausibility only.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Systematic Review of Antibody-siRNA Conjugates Targeting Myostatin in Murine Models for Muscle Mass Preservation
Systematic review and meta-analysis of all peer-reviewed studies in CD-1 lean mice using a single administration of antibody-siRNA conjugates targeting myostatin, comparing leg area and muscle mass over five weeks versus control groups, with standardized outcome measures and risk of bias assessment.
Double-Blind Randomized Trial of Antibody-siRNA Conjugate vs Saline Control in CD-1 Lean Mice for Muscle Mass Preservation
Randomized, double-blind, placebo-controlled trial in CD-1 lean mice: one group receives a single intravenous injection of the antibody-siRNA conjugate targeting myostatin, the control group receives saline; leg area and skeletal muscle mass are measured at baseline, day 7, day 14, day 21, and day 35; systemic myostatin levels are monitored.
Longitudinal Cohort Study of Muscle Mass Trajectory in CD-1 Lean Mice After Single Antibody-siRNA Conjugate Administration
Prospective cohort study following a group of CD-1 lean mice receiving a single antibody-siRNA conjugate injection and a matched control group without intervention, with serial measurements of leg area and muscle mass at weekly intervals for five weeks.
In Vitro Analysis of Antibody-siRNA Conjugate Uptake and Myostatin Suppression in Murine Skeletal Muscle Cells
Primary murine skeletal muscle cell cultures exposed to the antibody-siRNA conjugate; myostatin mRNA and protein levels measured at 24, 48, and 72 hours; cellular uptake confirmed via fluorescent labeling; no systemic variables included.
Single-Dose Antibody-siRNA Conjugate Study in CD-1 Lean Mice Measuring Muscle Mass and Myostatin Levels Over Five Weeks
Single-arm experimental study in CD-1 lean mice: one group receives a single injection of the conjugate; leg area, skeletal muscle mass, and myostatin levels in muscle and serum are measured at baseline and at weekly intervals for five weeks.