View

The Study

Apitegromab for lean mass preservation during tirzepatide-induced weight loss: a randomized, double-blind, placebo-controlled phase 2 trial.

In simple terms

This study is like a fair test where half the people got a new medicine and half got a sugar pill, and both groups were losing weight with the same drug. The group with the new medicine kept more muscle. That means the medicine probably helped, but we don’t know if it would work for everyone.

69%

Analysis score

69/ 90

Maximum 90 for a randomized controlled trial.

Where the score came from

Reporting0
Methodology85
Publication100
Statistical77
Study type (basis of the score)
Randomized Controlled Trial
Level 1b - Individual RCT
What’s the bottom line?

When people take tirzepatide to lose weight, they often lose muscle too. This study tested a new drug called apitegromab to see if it could stop that muscle loss.

Where does this study sit?

Systematic Reviews & Meta-analyses

Max 100

Randomized Trials

Max 90

Cohort Studies

Max 72

Case-Control

Max 58

Cross-Sectional

Max 44

Case Reports & Series

Max 30

Expert Opinion

Max 5
StrongerWeaker
Randomized Trials
Level 1b
69

69 / 100

Quality score

Participants are randomly assigned to treatment or control groups, minimizing bias. Considered the gold standard for testing whether an intervention causes an effect.

Can establish causation

Save studies & get personalized insights

Create a free account to save this study, track new evidence as it comes in, and get breakdowns of studies in the topics you care about.

Key takeaways

Summary

Based on the study abstract and findings.

  1. 1Yes — preserving muscle helps maintain metabolism, strength, and long-term health during weight loss, making this a meaningful improvement.
  2. 2People who got apitegromab lost 1.9 kg less muscle than those who got a placebo, even though both groups lost the same total weight.
  3. 3Muscle made up only 14.6% of weight loss with apitegromab vs.
  4. 430.2% without.
  5. 5The muscle-saving effect lasted 8 weeks after stopping the drug.

Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data

Publication

Journal

Nature medicine

Year

2026

Authors

R. Pratley, D. Denham, R. Trivedi, E. Watkins, L. Connery, J. Barnes, Dongzi Yu, J. Hong, C. Simard, K. Umans, Lan Liu, G. S. Tirucherai, J. Marantz

Open Access
Analysis v4
Fit Body Science verdict — we translate health studies into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.