Review finds tirzepatide weight loss includes 10-30% lean mass

The wire

1. 01A narrative review of ten randomized, observational and modelling studies found lean mass accounted for roughly 10% to 30% of total weight lost on tirzepatide, in line with expected physiology.
2. 02Clinicians counselling patients on dual GIP/GLP-1 therapy have a figure to anchor discussions of muscle preservation, resistance training and protein intake during treatment.
3. 03Most studies used bioelectrical impedance rather than DXA, functional outcomes were not measured, and heterogeneity in design limits firm conclusions.

From the source

Beyond weight loss: a narrative review of tirzepatide's impact on muscle and lean mass in people with overweight and obesity

Current medical research and opinion · 2026 Sep 28 · Wilkinson T, Ramzan R et al.