Most Common Side Effects of Wegovy
Wegovy (semaglutide), used for weight management, most often causes gastrointestinal issues. Clinical trials report these in over 5% of patients at the 2.4 mg maintenance dose: nausea (44%), diarrhea (30%), vomiting (24%), constipation (24%), and abdominal pain (20%). Less frequent but still common effects include headache (14%), fatigue (11%), dyspepsia (9%), dizziness (8%), bloating (7%), belching (6%), gastroesophageal reflux (5%), and hypoglycemia (low blood sugar, especially with other diabetes meds, 6%).[1][2]
Why Do These Side Effects Happen?
These stem from Wegovy's action as a GLP-1 receptor agonist, which slows gastric emptying and affects gut motility, leading to nausea and related symptoms. They typically peak during dose escalation (starting at 0.25 mg weekly, ramping up over 16 weeks) and often improve over time as the body adjusts.[1][3]
How Long Do Side Effects Last?
Most resolve within weeks of starting or dose increases, but nausea can persist in 10-20% of users. If severe, doctors may pause escalation or add anti-nausea meds like ondansetron. Long-term data from trials up to 68 weeks show reduced incidence after initial months.[1][2]
What Serious Side Effects Should Users Watch For?
Beyond common ones, risks include pancreatitis (rare, <1%), gallbladder issues (2-4%), kidney problems, or thyroid tumors (seen in rodents, human risk unclear). Stop use and seek care for severe abdominal pain, persistent vomiting, or vision changes. Heartburn or reflux worsens GERD in some.[1][3]
Tips to Manage Common Side Effects
Eat smaller, bland meals; avoid fatty/spicy foods; stay hydrated; take doses with food if tolerated. Over-the-counter options like antacids help reflux, while ginger or acupressure aids nausea. About 16% discontinue due to side effects, mostly GI-related.[1][2]
How Does Wegovy Compare to Ozempic or Mounjaro Side Effects?
Wegovy and Ozempic share semaglutide, so side effects mirror closely (nausea ~20-44% across doses). Mounjaro (tirzepatide) has similar GI rates but higher diarrhea (20-25%) and slightly less nausea in head-to-head data. All GLP-1s carry boxed warnings for thyroid cancer risk.[2][4]
Sources
[1]: Wegovy Prescribing Information (Novo Nordisk)
[2]: FDA Label for Wegovy
[3]: NEJM STEP Trials on Semaglutide
[4]: Clinical Comparison of GLP-1 Agonists (Drugs.com)