Journal September 26, 2026 4 min read

Common Misconceptions About Lean Mass Preservation

Lean mass preservation during weight loss is an active research area, but several misconceptions persist. This article examines what the evidence actually shows about investigational approaches, including trevogrumab and

peptides-pro Editorial

Lean mass preservation refers to the retention of skeletal muscle and other non-fat tissues during periods of weight reduction. In the context of obesity pharmacotherapy, it is a recognised challenge: GLP-1 receptor agonists (GLP-1RAs) have transformed obesity treatment, achieving weight loss previously considered attainable only with bariatric surgery, but they have revealed important limitations, including weight loss plateaus, substantial inter-individual variability, and weight regain upon discontinuation [1]. Among the strategies under investigation to address these limitations is the combination of muscle-preserving agents with GLP-1RAs. One such approach involves trevogrumab, an investigational antibody, and garetosmab, another investigational antibody, administered alongside semaglutide [2].

The work centres on the myostatin/activin signalling pathway, a receptor family implicated in the regulation of skeletal muscle mass.

Research Studies

Trevogrumab and garetosmab in combination with semaglutide in adults with obesity

A clinical trial is investigating trevogrumab and garetosmab when taken with semaglutide in adult patients with obesity for weight loss, fat loss, and lean mass preservation [2]. The study is being conducted in three parts: Part A focuses on healthy participants, while Parts B and C focus on participants with obesity. The aim of Part A is to assess the safety and tolerability of the study drug in healthy participants; the aim of Parts B and C is to evaluate the safety and effectiveness of the study drug when combined with semaglutide (Wegovy®) [2]. The trial is also examining several other research questions [2].

Trevogrumab and garetosmab: mechanism of action in lean mass preservation

Trevogrumab and garetosmab are experimental drugs being studied in combination with semaglutide [2]. The available evidence does not specify their precise mechanism of action, but they are being investigated for their potential to preserve lean mass during weight loss [2].

Semaglutide and lean mass preservation in adults with obesity

Semaglutide is a GLP-1 receptor agonist approved for obesity treatment [1]. GLP-1-based therapies have been associated with weight loss plateaus, inter-individual variability, and weight regain upon discontinuation [1]. The trial described above is testing whether the addition of trevogrumab and garetosmab to semaglutide can improve lean mass preservation in adults with obesity [2].

Lean mass preservation: limitations of current GLP-1-based therapies

Existing reviews have focused predominantly on approved GLP-1RAs, with limited synthesis of emerging multi-receptor agonists, oral formulations, and body composition outcomes [1]. This gap highlights the need for next-generation approaches that address not only weight loss but also the quality of weight lost, including lean mass [1].

Multi-receptor agonists and lean mass preservation: emerging research

The era of multi-receptor agonists and next-generation metabolic modulators is being explored to overcome the limitations of current GLP-1-based therapies [1]. These approaches may offer alternative or complementary strategies for weight management, but their effects on lean mass preservation are not yet fully characterised [1].

Animal and in vitro evidence for lean mass preservation strategies

The evidence block does not provide animal-only or in vitro data on lean mass preservation. The studies cited are clinical trials and reviews in human populations [1][2].

Inter-individual variability in lean mass preservation during weight loss

Substantial inter-individual variability is a recognised limitation of GLP-1-based therapies [1]. This variability may extend to lean mass outcomes, but the evidence block does not provide specific data on this point.

Weight regain and lean mass preservation after discontinuation

Weight regain upon discontinuation is a known limitation of GLP-1-based therapies [1]. The impact of weight regain on lean mass preservation is not detailed in the evidence block.

Safety and tolerability of trevogrumab and garetosmab in healthy participants

Part A of the ongoing trial is focused on assessing the safety and tolerability of the study drug in healthy participants [2]. Results from this part are not yet available in the evidence block.

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