What are the potential side effects of Ozempic (semaglutide)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: September 28, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Ozempic (Semaglutide) Side Effects

Gastrointestinal side effects are the most common adverse reactions to Ozempic (semaglutide), including nausea (40%), vomiting (16%), diarrhea, and dyspepsia, which are typically dose-dependent and often transient. 1

Common Side Effects

Gastrointestinal Effects

  • Nausea (40% vs 14.8% with placebo)
  • Vomiting (16% vs 4.3% with placebo)
  • Diarrhea
  • Abdominal pain
  • Constipation
  • Dyspepsia (indigestion)
  • Gastroesophageal reflux 2, 1

Other Common Side Effects

  • Injection site reactions
  • Elevated heart rate
  • Hypoglycemia (especially when combined with insulin or sulfonylureas) 2

Serious Side Effects

Pancreatic Issues

  • Pancreatitis - Stop using Ozempic immediately and contact healthcare provider if severe abdominal pain occurs (with or without vomiting) 3
  • FDA label instructs to discontinue if pancreatitis is suspected and not restart if confirmed 3

Gallbladder Disorders

  • Cholelithiasis (gallstones)
  • Gallstone-related complications 2

Gastrointestinal Complications

  • Severe constipation
  • Small bowel obstruction/ileus progression 2

Kidney Problems

  • Acute kidney injury - particularly when initiating or increasing dose in patients with existing kidney disease
  • Dehydration from gastrointestinal side effects may worsen kidney function 3

Vision Changes

  • Changes in vision during treatment should be reported to healthcare provider
  • Diabetic retinopathy complications have been reported, particularly with rapid improvement in blood glucose control 2, 3

Serious Allergic Reactions

  • Stop using and seek immediate medical help for symptoms like itching, rash, or difficulty breathing 3

Thyroid Concerns

  • Black box warning: Risk of thyroid C-cell tumors in rodents (human relevance not determined)
  • Contraindicated in patients with personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2 2, 1, 3

Management of Side Effects

Adverse effect Management
Nausea and vomiting Avoid in gastroparesis; start at low dose and titrate slowly
Dyspepsia Start at low dose and titrate slowly
Diarrhea Reduce meal size
Gastrointestinal reflux Limit alcohol and carbonated drinks
Constipation Avoid high-fat diet
Gallbladder disorders Monitor for symptoms
Cardiac arrhythmia/tachycardia If symptomatic, monitor and consider beta blockers
[2,1]

Dosing Considerations to Minimize Side Effects

The standard titration protocol for semaglutide is designed to minimize gastrointestinal side effects:

Week Semaglutide Dose
1-4 0.25 mg weekly
5-8 0.5 mg weekly
9-12 1.0 mg weekly
13-16 1.7 mg weekly
17+ 2.4 mg weekly (maintenance)
[1]

Special Precautions

  • Pretreatment Assessment: Current pretreatment assessment approaches are often underdeveloped, particularly regarding disease history that might affect semaglutide use 4

  • Medication Absorption: Monitor for potential consequences of delayed absorption of oral medications, particularly those with narrow therapeutic index like warfarin 2

  • Contraception: Women using oral hormonal contraception should use or add a non-oral contraception method for 4 weeks after initiation and dose escalations 2

  • Pregnancy: Contraindicated in women who are or may become pregnant 2

  • Overdose Management: In case of overdose, supportive care is recommended, including antiemetics, correction of fluid and electrolyte imbalances, and monitoring for hypoglycemia 5

By understanding these potential side effects and following appropriate management strategies, patients can better navigate treatment with Ozempic while minimizing adverse reactions.

References

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.