What are the side effects of Ozempic (semaglutide)?

Side Effects of Ozempic (Semaglutide)

Ozempic commonly causes gastrointestinal side effects—particularly nausea, vomiting, diarrhea, constipation, and abdominal pain—which are typically dose-dependent and most pronounced during initial treatment or dose escalation. 1, 2

Most Common Side Effects

Gastrointestinal Effects (Most Frequent)

• Nausea, vomiting, diarrhea, abdominal pain, and constipation are the most common adverse effects, occurring in ≥5% of patients treated with Ozempic 2
• These gastrointestinal symptoms are dose-dependent and typically more severe during initial treatment or when increasing doses 1, 3
• Gradual dose titration is recommended to minimize these gastrointestinal side effects 1, 3
• Most gastrointestinal effects are transient and mild-to-moderate in severity, subsiding with time 4

Practical Management of GI Side Effects

• To manage nausea and vomiting, reduce meal size 1
• To reduce reflux symptoms, limit alcohol and carbonated drinks 1
• Avoid high-fat diets to help with constipation 1

Serious Adverse Events

Overall Risk Profile

• Clinical trials demonstrate a 38% higher risk of serious adverse events with semaglutide compared to placebo 1, 3

Specific Serious Complications

Pancreatitis:

• Increased risk of inflammation of the pancreas 1, 3
• Stop using Ozempic immediately and seek medical attention if you develop severe abdominal pain that will not go away, with or without vomiting 2
• The pain may radiate from abdomen to back 2

Gallbladder Disease:

• Increased risk of cholelithiasis (gallstones) and cholecystitis 1, 3
• Regular monitoring for gallbladder disease is advised 1

Kidney Problems:

• Risk of acute kidney injury, particularly in patients with pre-existing kidney disease 3
• Diarrhea, nausea, and vomiting may cause dehydration, which can worsen kidney problems 2
• It is important to drink fluids to help reduce your chance of dehydration 2
• Regular monitoring of renal function is advised, especially in those experiencing severe gastrointestinal side effects 1

Cardiovascular Events:

• Acute myocardial infarction has been reported in clinical trials 1, 3
• However, semaglutide has also been shown to reduce cardiovascular death, heart attack, and stroke in adults with obesity or overweight and cardiovascular disease (major cardiovascular events occurred in 6.5% with semaglutide vs. 8% with placebo) 1

Vision Changes:

• Risk of diabetic retinopathy complications 1
• Tell your healthcare provider if you have changes in vision during treatment with Ozempic 2

Hypoglycemia Risk

• Your risk for low blood sugar is higher if you use Ozempic with another medicine that can cause low blood sugar, such as sulfonylureas or insulin 1, 2
• Signs and symptoms include: dizziness, blurred vision, anxiety, sweating, slurred speech, hunger, confusion, shakiness, weakness, headache, fast heartbeat, and feeling jittery 2

Other Notable Side Effects

• Injection site reactions 1
• Insomnia has been documented as a side effect 3
• Risk of suicidal ideation has been reported 1
• Cardiac arrhythmia/tachycardia may occur; if symptomatic, monitoring and consideration of beta blockers may be necessary 1
• Delayed gastric emptying, which may affect absorption of other medications 3
• Severe allergic reactions: Stop using Ozempic and get medical help immediately if you develop itching, rash, or difficulty breathing 2

Absolute Contraindications

Thyroid Cancer Risk:

• Ozempic carries an FDA Black Box Warning regarding the risk of thyroid C-cell tumors based on rodent studies 1
• Contraindicated in patients with personal or family history of medullary thyroid cancer or multiple endocrine neoplasia syndrome type 2 1, 3

Pregnancy and Breastfeeding:

• Pregnancy or breastfeeding is an absolute contraindication for semaglutide use 1

Special Populations Requiring Caution

Gastroparesis:

• Patients with severe gastroparesis may experience worsened symptoms due to delayed gastric emptying 1
• Not recommended in patients with clinically meaningful gastroparesis 1

Prior Gastric Surgery:

• Careful consideration required for patients with prior gastric surgery, including bariatric surgery 1

Renal Impairment:

• Can be used with caution in severe renal impairment or end-stage renal disease, unlike some other GLP-1 receptor agonists 1
• Patients with severe renal impairment require careful monitoring due to increased risk of gastrointestinal side effects and potential dehydration 1

Oral Contraceptives:

• For patients using oral hormonal contraceptives, consider switching to a non-oral contraceptive method or adding a barrier method for 4 weeks after initiation and after each dose escalation due to potential reduced efficacy from delayed gastric emptying 1

Monitoring Recommendations

• Regular monitoring of renal function, especially during severe gastrointestinal symptoms 1
• Monitor for signs of pancreatitis 1
• Monitor for gallbladder disease 1
• Check blood sugar as directed by your healthcare provider 2
• Regular blood tests including blood sugar levels and hemoglobin A1C 2
• Monitor sleep disturbances, especially during initial titration phase 3

Common Pitfalls to Avoid

• Do not mix insulin and Ozempic together in the same injection 2
• Do not share your Ozempic pen with other people, even if the needle has been changed, as this may transmit serious infections 2
• Discontinuation due to gastrointestinal events occurs in approximately 4.5% of patients 4
• If more than 5 days have passed since a missed dose, skip it and take your next dose on the regularly scheduled day 2