# What are the most common side effects of GLP-1 weight-loss drugs?

Per the FDA-approved Wegovy label, the most common side effects at incidence ≥5% are nausea, diarrhea, vomiting, constipation, and abdominal pain, along with headache, fatigue, indigestion, dizziness, bloating, burping, flatulence, gastroenteritis, GERD, and nasopharyngitis; the label also carries a boxed warning about thyroid C-cell tumors observed in rodents. The U.S. Food and Drug Administration states, in its FDA-approved Wegovy prescribing information, Adverse Reactions (6.1) (August 2025): "Most common adverse reactions (incidence ≥5%) in adults or pediatric patients aged 12 years and older are: nausea, diarrhea, vomiting, constipation, abdominal pain, headache, fatigue, dyspepsia, dizziness, abdominal distension, eructation, hypoglycemia in patients with type 2 diabetes, flatulence, gastroenteritis, gastroesophageal reflux disease, and nasopharyngitis."

## The FDA-listed common side effects (verbatim from the label)
Per the current Wegovy Prescribing Information (2025), the listed adverse reactions at incidence ≥5% in adults or pediatric patients aged 12 years and older are: "nausea, diarrhea, vomiting, constipation, abdominal pain, headache, fatigue, dyspepsia, dizziness, abdominal distension, eructation, hypoglycemia in patients with type 2 diabetes, flatulence, gastroenteritis, gastroesophageal reflux disease, and nasopharyngitis."

## The serious warnings the label calls out
- Boxed warning: risk of thyroid C-cell tumors observed in rodents; the human risk is unknown; contraindicated in patients with a personal or family history of medullary thyroid carcinoma (MTC) or MEN 2 syndrome.
- Acute pancreatitis — discontinue if suspected.
- Acute gallbladder disease.
- Hypoglycemia (especially when combined with insulin or an insulin secretagogue).
- Acute kidney injury due to volume depletion (from vomiting and diarrhea).
- Severe gastrointestinal adverse reactions — not recommended in patients with severe gastroparesis.
- Hypersensitivity reactions, including anaphylaxis and angioedema.
- Diabetic retinopathy complications in patients with type 2 diabetes.
- Heart rate increase — monitor at regular intervals.
- Suicidal behavior and ideation — monitor for depression or suicidal thoughts.
- Pulmonary aspiration during general anesthesia or deep sedation.

## What this list is (and isn''t)
This is the FDA-approved label. It is drawn from clinical-trial data pooled by Novo Nordisk and reviewed by the FDA. It does not describe every possible reaction or every real-world case. Anyone experiencing severe symptoms should contact a licensed clinician and, if serious, report to the FDA MedWatch program at 1-800-FDA-1088.

## Source
FDA-approved Wegovy Prescribing Information (August 2025 revision), accessdata.fda.gov/drugsatfda_docs/label/2025/215256s024lbl.pdf

## Sources
- U.S. Food and Drug Administration — FDA-approved Wegovy prescribing information, Adverse Reactions (6.1) (August 2025): https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/215256s024lbl.pdf

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Canonical: https://directanswersrx.com/answers/glp1-side-effects
Author: Jason Burns (Editorial Steward) — https://directanswersrx.com/steward
Published: 2026-07-19T23:35:42.249Z
Modified: 2026-07-19T23:35:42.249Z
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