Most Frequent Side Effects of Wegovy
Wegovy (semaglutide), used for weight management, most often causes gastrointestinal issues. These affect over 5% of users in clinical trials and include nausea (44%), diarrhea (30%), vomiting (24%), constipation (24%), and abdominal pain (20%). These typically start early in treatment and decrease over time.[1][2]
Why Do These Happen and How Long Do They Last?
Semaglutide slows gastric emptying, leading to these gut-related effects. Nausea peaks in the first 4-8 weeks as patients titrate up from 0.25 mg weekly doses. Most resolve within weeks, but up to 10% stop due to intolerance.[1][3]
Serious but Less Common Side Effects
Rarely, Wegovy triggers gallbladder issues like cholelithiasis (1.6%) or acute pancreatitis (<1%). Hypoglycemia risk rises if combined with insulin or sulfonylureas. Thyroid C-cell tumors occurred in rodent studies, prompting boxed warnings, though human risk remains unclear.[1][2]
What Patients Report in Real-World Use
Post-marketing data shows injection-site reactions (redness, itching) in 13%, fatigue, headache, and dizziness. Women report more nausea; some experience hair loss or acid reflux not highlighted in trials.[3][4]
Managing Side Effects
Start low and go slow on dosing. Eat smaller meals, stay hydrated, and avoid fatty foods to ease GI symptoms. Doctors often prescribe anti-nausea meds like ondansetron. Consult a provider before stopping.[2][3]
Who Faces Higher Risks?
Pregnant or breastfeeding individuals should avoid it due to fetal harm risks. Those with medullary thyroid carcinoma history or multiple endocrine neoplasia syndrome type 2 are contraindicated. Monitor kidney function, as dehydration from vomiting can worsen it.[1][2]
[1] Novo Nordisk, Wegovy Prescribing Information (FDA-approved label, 2023). https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/215256s007lbl.pdf
[2] Novo Nordisk Wegovy clinical trials summary. https://www.wegovy.com/content/experience-fragments/footer/footer-master.content/footer-master.html
[3] Drugs.com, Wegovy side effects patient reviews. https://www.drugs.com/sfx/wegovy-side-effects.html
[4] FDA Adverse Event Reporting System (FAERS) data on semaglutide (2023). https://www.fda.gov/drugs/questions-and-answers-fdas-adverse-event-reporting-system-faers/fda-adverse-event-reporting-system-faers-public-dashboard