Side effects
Wegovy side effects
Stomach and bowel effects are the most common side effects of Wegovy.1 In adult weight trials of the 2.4 mg injection, nausea affected 44% and diarrhea 30%, against 16% each on placebo.1 The boxed warning covers thyroid C-cell tumors seen in rodents; other warnings include pancreatitis, gallbladder disease and kidney injury.1
This page summarizes published sources for information only. It is not medical advice and does not tell anyone to use a product. Questions about your own health belong with a licensed clinician. For questions about an order or a product, contact us.
Most common side effects
These rates come from the label's adult weight trials of the 2.4 mg weekly injection, and each reaction was more frequent on Wegovy than on placebo.1
| Side effect | Wegovy 2.4 mg1 | Placebo1 |
|---|---|---|
| Nausea | 44% | 16% |
| Diarrhea | 30% | 16% |
| Vomiting | 24% | 6% |
| Constipation | 24% | 11% |
| Abdominal pain | 20% | 10% |
| Headache | 14% | 10% |
| Fatigue | 11% | 5% |
| Indigestion (dyspepsia) | 9% | 3% |
| Dizziness | 8% | 4% |
| Bloating (abdominal distension) | 7% | 5% |
| Belching | 7% | under 1% |
| Gas (flatulence) | 6% | 4% |
| Gastroenteritis | 6% | 4% |
| Acid reflux (GERD) | 5% | 3% |
| Gastritis | 4% | 1% |
Most stomach and bowel effects occurred while the dose was being raised.1 Any stomach or bowel side effect was reported by 73% on Wegovy and 47% on placebo, and a severe one by 4.1% and 0.9%.1 The label raises the dose one step every 4 weeks to reduce these effects.1
At the 7.2 mg dose
Wegovy HD, the 7.2 mg weekly dose, brought higher rates of most common reactions than 2.4 mg in the label's comparison.1
| Reaction | 7.2 mg1 | 2.4 mg1 | Placebo1 |
|---|---|---|---|
| Nausea | 39% | 35% | 13% |
| Vomiting | 22% | 16% | 6% |
| Constipation | 20% | 19% | 8% |
| Abdominal pain | 12% | 9% | 7% |
| Fatigue | 11% | 9% | 5% |
| Dysesthesia | 22% | 6% | 0.3% |
Dysesthesia is altered skin sensation, such as tingling, burning or skin that feels sensitive, and it rises with dose.1 In the earlier 2.4 mg weight trials it affected 2% against 1% on placebo.1
With the tablets
With 25 mg Wegovy tablets, the types and rates of common side effects were similar to the injection.1 Severe stomach and bowel reactions occurred in 2% against 0% on placebo, and dysesthesia in 5% against 0%.1 Gallstones occurred in 2.5% on tablets against 1% on placebo.1 Breastfeeding is not recommended with the tablets: their SNAC ingredient reaches breast milk and may build up in infants, and semaglutide forms without SNAC exist.1 The label notes that slower stomach emptying may change how other oral medicines are absorbed; with semaglutide tablets, levothyroxine exposure rose 33%.1
In children 12 and older
Teens on 2.4 mg reported nausea (42% against 18% on placebo), vomiting (36% against 10%), diarrhea (22% against 19%) and abdominal pain (15% against 6%).1 Gallstones occurred in 3.8% of teens on Wegovy and in none on placebo.1
Less common reactions
- Injection site reactions such as itching, redness, swelling or hardening: 1.4% against 1% on placebo.1
- Low blood pressure, 1.3% against 0.4%, and fainting, 0.8% against 0.2%.1
- Taste changes (dysgeusia), 1.7% against 0.5%, and appendicitis, 0.5% against 0.2%.1
- Hip and pelvis fractures in the 3-year heart trial: 1% against 0.2% in women, and 2.4% against 0.6% in people aged 75 and older.1
- Kidney stones in the heart trial: 1.2% against 0.8%.1
- Resting heart rate rose by a mean of 1 to 4 beats per minute.1 At some visit, 26% on Wegovy and 16% on placebo had a rise of 20 beats per minute or more.1
Serious warnings on the label
- Thyroid C-cell tumors (boxed warning). In mice and rats, thyroid C-cell tumors became more common with higher semaglutide doses and longer treatment, at exposures seen in clinical use.1 Whether it causes these tumors in people, including medullary thyroid carcinoma, is unknown.1 The label asks patients to report a neck mass, trouble swallowing, shortness of breath or lasting hoarseness.1
- Pancreatitis. It was confirmed in 4 Wegovy patients in adult weight trials (0.2 cases per 100 patient-years) against 1 on placebo.1 Persistent or severe stomach pain, sometimes spreading to the back, is the warning sign, and Wegovy is stopped if pancreatitis is suspected.1
- Gallbladder disease. Gallstones occurred in 1.6% on the injection against 0.7% on placebo, and gallbladder inflammation (cholecystitis) in 0.6% against 0.2%.1 The risk stayed above placebo even after accounting for weight loss.1
- Low blood sugar. Among adults with type 2 diabetes, clinically significant low blood sugar (below 54 mg/dL) occurred in 6.2% against 2.5%.1 The risk is higher when Wegovy is combined with insulin or a sulfonylurea.1
- Kidney injury. Acute kidney injury, sometimes needing dialysis, was reported mostly in people dehydrated by nausea, vomiting or diarrhea.1 The Medication Guide advises drinking fluids to lower the chance of dehydration.1
- Severe stomach and bowel reactions. These affected 4.1% on the injection against 0.9% on placebo.1 Wegovy is not recommended in severe gastroparesis.1
- Diabetic eye disease. In a 2-year trial of semaglutide 0.5 mg and 1 mg in type 2 diabetes, retinopathy complications occurred in 3% against 1.8% on placebo.1 People with diabetes are asked to report vision changes.1
- Surgery and sedation. Wegovy slows stomach emptying, and rare cases of food entering the lungs under anesthesia have been reported with GLP-1 drugs.1 The label asks patients to tell every provider before a planned procedure.1
- Pregnancy. Weight loss offers no benefit in pregnancy and may harm the fetus.1
- Shared pens. A FlexTouch pen is never shared between people, even with a new needle, because of the risk of spreading blood-borne infections.1
Reported after approval
These reactions come from voluntary reports made after approval, so their frequency cannot be reliably estimated and a link to the drug is not always established.1 They are pancreatitis (sometimes fatal), ileus, intestinal blockage, severe constipation including fecal impaction, anaphylaxis, angioedema, rash, hives, acute kidney injury and pulmonary aspiration during anesthesia.1
In June 2025, the European Medicines Agency's safety committee reviewed NAION, an eye condition that can affect vision.2 It concluded that NAION is a very rare side effect of semaglutide medicines, including Wegovy, affecting up to 1 in 10,000 people taking semaglutide, and that treatment should stop if NAION is confirmed.2 The agency advises contacting a doctor without delay about sudden vision loss or rapidly worsening eyesight.2 The US Wegovy label, revised in June 2026, does not list NAION.1
Suicidal thoughts: the FDA review
On January 13, 2026, FDA asked makers to remove the suicidal behavior and ideation warning from the Wegovy, Saxenda and Zepbound labels.3 FDA's meta-analysis pooled 91 placebo-controlled GLP-1 trials covering 107,910 patients and found no rise in suicidal thoughts or behavior.3 FDA still advises anyone with new or worsening depression or suicidal thoughts to tell a health care professional, and to call or text 988 in a crisis.3
Related pages
Start with the Wegovy profile for the overview. The step-by-step label schedule is in Wegovy dosage, and the trial results behind each use are in Wegovy benefits and uses. Pen technique is in Wegovy injection sites and pen use. Effects shared across the drug class are compared in GLP-1 side effects.
More on Wegovy
Wegovy dosage
Published dosing information for Wegovy from labels and studies, with its source, and why it is not advice for you.
Wegovy injection sites and pen use
Where Wegovy is injected, how the pen is used, and site rotation, from the FDA label and Instructions for Use. Sourced and reviewed.
Wegovy benefits and uses
What published sources report about Wegovy and its uses, with the evidence level of each finding. No promises.
Frequently asked questions
What disqualifies you from taking Wegovy?
The label lists two contraindications.1 One is a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).1 The other is a prior serious allergic reaction to semaglutide or any Wegovy ingredient.1 Wegovy is also not recommended in severe gastroparesis, and the label does not recommend combining it with another semaglutide product or any other GLP-1 receptor agonist.1 Before a planned pregnancy, the label says to stop at least 2 months ahead because of semaglutide's long half-life.1
What are the symptoms of an allergic reaction to Wegovy?
The Medication Guide lists swelling of the face, lips, tongue or throat; problems breathing or swallowing; severe rash or itching; fainting or feeling dizzy; and a very rapid heartbeat.1 It tells patients to stop Wegovy and get medical help right away if these appear.1 Anaphylaxis and angioedema have been reported since approval, and a past serious reaction to semaglutide rules Wegovy out.1
Why are people stopping Wegovy?
Mostly because of stomach and bowel effects.1 In the label's adult weight trials, 6.8% stopped because of a side effect, against 3.2% on placebo, and nausea, vomiting and diarrhea were the most common reasons.1 Stomach and bowel effects alone led 4.3% to stop, against 0.7% on placebo.1 In the SELECT heart trial, with a median of about 3 years on treatment, 16% on Wegovy and 8% on placebo stopped for an adverse event.1 With the 25 mg tablets, the rates were 6.9% and 5.9%.1
Written by D2C Peptides Editorial Team.
Pending qualified review.
Updated .
Sources
- WEGOVY (semaglutide) injection and WEGOVY (semaglutide) tablets: Full Prescribing Information, Medication Guide and Instructions for Use (revised 06/2026). U.S. Food and Drug Administration (Novo Nordisk labeling), 2026.
- PRAC concludes eye condition NAION is a very rare side effect of semaglutide medicines Ozempic, Rybelsus and Wegovy. European Medicines Agency (news, 6 June 2025), 2025.
- FDA Requests Removal of Suicidal Behavior and Ideation Warning from Glucagon-Like Peptide-1 Receptor Agonist (GLP-1 RA) Medications. U.S. Food and Drug Administration (Drug Safety Communication, January 13, 2026), 2026.