Common Side Effects of Ozempic (Semaglutide)
Gastrointestinal side effects are the most common adverse reactions to Ozempic (semaglutide), including nausea, vomiting, diarrhea, abdominal pain, and constipation. These typically occur during dose escalation and often diminish over time with continued use 1.
Major Side Effects by Category
Gastrointestinal Effects
- Nausea, vomiting, and diarrhea (most common side effects) 1, 2
- Abdominal pain and constipation 1
- Dyspepsia, gastroesophageal reflux disease, and eructation (belching) 2
- Delayed gastric emptying, which can affect absorption of oral medications 2
- Risk of severe gastrointestinal disorders including small bowel obstruction and ileus progression 2
Serious Adverse Events
- Pancreatitis: Patients should discontinue semaglutide and seek immediate medical attention if severe abdominal pain occurs 1, 3
- Thyroid C-cell tumors (black box warning): Risk observed in rodents; human relevance not determined 2
- Gallbladder disease: Increased risk of cholelithiasis and gallstone-related complications 2, 3
- Diabetic retinopathy complications: Particularly in patients with pre-existing retinopathy 2, 3
- Acute kidney injury: Especially in patients with pre-existing kidney disease or those experiencing dehydration from gastrointestinal side effects 2, 1
Metabolic Effects
Other Reported Side Effects
- Injection site reactions 2
- Headache and dizziness 1
- Fatigue 2
- Serious allergic reactions (rare): Can include itching, rash, or difficulty breathing 1
- "Ozempic face": Facial volume loss and premature aging appearance due to rapid weight loss 4
Contraindications
- Personal or family history of medullary thyroid carcinoma 2, 1
- Multiple endocrine neoplasia syndrome type 2 (MEN2) 1, 5
- Pregnancy and breastfeeding 2, 5
- Previous serious hypersensitivity reaction to semaglutide 2
Special Precautions and Monitoring
- Careful monitoring in patients with history of pancreatitis 2, 3
- Use caution in patients with pre-existing diabetic retinopathy 2, 3
- Monitor renal function, especially when initiating or increasing dose in patients with kidney disease 2, 1
- Consider potential delayed absorption of oral medications, particularly those with narrow therapeutic index 2
- Patients should be adequately hydrated to reduce risk of dehydration and associated kidney problems 1
- Pre-treatment assessment should include screening for thyroid abnormalities, pancreatitis history, and retinopathy 6
Monitoring Recommendations
- Regular monitoring of blood glucose levels, especially if also taking insulin or sulfonylureas 1
- Monitor for signs of pancreatitis during treatment 1
- Regular eye examinations for patients with history of diabetic retinopathy 2
- Monitor for gallbladder disease symptoms 2
- Assess renal function, particularly in patients with pre-existing kidney disease 2
Risk Management
- Start with the lowest dose and titrate slowly to minimize gastrointestinal side effects 2
- Ensure adequate hydration to prevent dehydration from gastrointestinal side effects 1
- Consider dose adjustments of concomitant medications that can cause hypoglycemia 2
- Discontinue if pancreatitis is suspected 1
- Advise patients to report severe abdominal pain, visual changes, or allergic reactions immediately 1
Despite these potential side effects, semaglutide has shown significant benefits for weight loss and glycemic control with an overall favorable risk/benefit profile for most eligible patients 3, 7.