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SERIES: MYTHS READ AGAINST THE SCIENCE

Slower stomach emptying is how GLP-1 works, paralysis overstates it

Gastroparesis vs Slowing

There is a medical condition called gastroparesis: severe, chronic delayed stomach emptying, usually diagnosed in people with long-standing diabetes or after certain abdominal surgeries. Routine delayed emptying on semaglutide is not the same as diagnosed severe gastroparesis. The label does say semaglutide delays gastric emptying, and rare severe or persistent retention-like presentations belong in clinical evaluation.

What the Trials Show

In adult Wegovy injection weight-reduction trials and the pooled STEP 1-3 semaglutide 2.4 mg analysis, severe gastrointestinal adverse reactions were reported in 4.1% of semaglutide-treated adults versus 0.9% on placebo. That rate is not the same thing as stomach paralysis or gastroparesis. A specific semaglutide 2.4 mg substudy in adults with obesity assessed gastric emptying at week 20 indirectly using paracetamol absorption and found no evidence of delayed gastric emptying at that point. The Wegovy label says it is not recommended in patients with severe gastroparesis.

What this means

References2 sources

How to read these sources

This article uses primary sources and reviews to separate mechanism, human evidence, and context.

Human TrialStudies in people
Official LabelRegulator documents
Show 3 more source types
ReviewExpert synthesis
MechanismCell and pathway logic
Public UpdateNews or announcements
  1. Human Trial

    Diabetes, Obesity and Metabolism

    Wiley

    Wharton, S., et al. · 2022 Gastrointestinal tolerability of once-weekly semaglutide 2.4 mg in adults with overweight or obesity, and the relationship between gastrointestinal adverse events and weight loss Read source

    Used Here For

    Grounding the stomach-paralysis question in pooled STEP 1 to 3 data on severe gastrointestinal events.

    Good For

    Pooled trial data on how often severe gastrointestinal events occurred.

    Not For

    Diagnosing gastroparesis or giving personal treatment advice.

    Diabetes, Obesity and Metabolism 24(1):94-105
    PMID 34514682
  2. Official Label

    FDA-approved prescribing information (Wegovy)

    U.S. Food and Drug Administration / Novo Nordisk

    Novo Nordisk · 2026 WEGOVY (semaglutide) prescribing information: 5.6 Severe Gastrointestinal Adverse Reactions Read source

    Used Here For

    Checking the approved label's warning on severe gastrointestinal adverse reactions.

    Good For

    The FDA-approved warning language on severe gastrointestinal reactions.

    Not For

    Diagnosing gastroparesis or giving personal treatment advice.

    FDA-approved labeling, DailyMed (National Library of Medicine), updated June 18, 2026