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Using GLP-1s

Least significant change (DXA precision)

The smallest difference between two DXA scans that reflects real change rather than measurement noise — anything below it should be read as "no measurable change."

By the glp1.how editorial teamReviewed

Least significant change (LSC) is a precision statistic used with DXA scans. Every scanner has a small amount of measurement error even when nothing about your body has changed; the LSC is the size of difference between two scans that is large enough (at 95% confidence) to be a real change rather than that error. Facilities calculate it by scanning the same people twice and measuring the spread.

For someone tracking a GLP-1 journey, LSC is the difference between a meaningful result and a misread. A lean-mass "loss" of 300 grams between scans on a machine whose LSC for lean mass is 1 kg is not evidence of anything — it is inside the noise. Ask the facility for its LSC values, get repeat scans on the same machine, and treat changes smaller than the LSC as "no measurable change." See reading your DXA results over time. The International Society for Clinical Densitometry (external link) asks each facility to calculate its own LSC at 95% confidence from its own repeat scans, not from manufacturer figures.

dxaleast-significant-changebody-compositiontracking-progress

Revision history

Updated 1 time since Sep 2, 2026 · show changes
  1. v2

    Body revised

  2. v1

    Change tracking began

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Related terms

  • Lean mass · Body weight from everything other than fat: mostly muscle, plus organs and water, and in the broad sense bone. On a DXA report, lean mass usually leaves bone out.
  • GLP-1 · A gut hormone (glucagon-like peptide-1) that stimulates insulin release, slows digestion, and reduces appetite; the target of drugs like semaglutide and liraglutide.

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