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

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