How much protein do I need on a GLP‑1?
GLP-1 protein target
kg
Daily protein target
96–128 g protein / day
Spread over ~4 meals ≈ 24–32 g each — pair with resistance training at least 3×/week.
Estimate only: actual body weight × 1.2–1.6 g/kg (2025 joint clinical advisory: ACLM, ASN, OMA, TOS). These targets are proposed, not established for GLP-1 populations, and preserve muscle only alongside resistance training. Clinicians may adjust for body composition. Not medical advice — discuss your target with your clinician.
The short version
- In the SEMALEAN study, semaglutide reduced fat mass by 14% at 7 months and 18% at 12 months; lean mass dipped ~3 kg initially but stabilized — so body composition ratio improved even as scale weight dropped.
- SURMOUNT-1 data show tirzepatide (Zepbound) users lost ~10.9% of lean mass, with about 25% of total weight lost coming from lean tissue.
- Lean mass loss as a share of total weight lost ranges from 15% to over 40% across GLP‑1 trials — the spread depends heavily on resistance training and protein intake.
- Adults over 65 carry the highest risk: skeletal muscle mass declines roughly 3–8% per decade after age 30 and faster after 60, leaving many older patients with little buffer before sarcopenic thresholds are crossed.
- A 2025 joint clinical advisory proposes higher protein targets of 1.2–1.6 g/kg/day during active weight loss, combined with strength training at least 3×/week, to preserve lean mass on GLP‑1 therapy.
- Muscle quality (intramuscular fat infiltration) actually improves on GLP‑1s — the concern is quantity, not quality, and the effect is largely blunted with the right lifestyle inputs.
The full guide
GLP‑1 Muscle Loss: What Ozempic, Wegovy, and Zepbound Do to Your Lean Mass
8 min read · Sean Moshrefi, PharmD, MS
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