Most people on Wegovy get at least one side effect, and it is usually in the gut. In the label's adult weight trials, 73% of people on Wegovy injection reported a digestive side effect, against 47% on placebo [1]. The numbers below come from the current US prescribing information (June 2026). Wegovy is semaglutide, the same molecule as Ozempic; for what the drug is and who it is approved for, see our Wegovy guide.
Wegovy injection has three approved uses. It lowers the risk of heart attack, stroke and heart-related death in adults with heart disease and obesity or overweight. It treats weight long term in adults and children 12 and older with obesity, and in adults with overweight plus a weight-related condition. It also treats a fatty liver disease with scarring (MASH), under accelerated approval. Wegovy tablets carry the heart and weight indications for adults [1].
Most of Wegovy's common side effects are digestive
The label's main table pools three placebo-controlled trials: 2,116 adults on Wegovy 2.4 mg for up to 68 weeks and 1,261 on placebo [1]. The 7.2 mg column comes from two newer trials of the Wegovy HD dose, which had their own placebo group, so read each column against its own placebo rather than across.
| Side effect | Placebo | Wegovy 2.4 mg |
|---|---|---|
| Nausea | 16 | 44 |
| Diarrhea | 16 | 30 |
| Vomiting | 6 | 24 |
| Constipation | 11 | 24 |
| Abdominal pain | 10 | 20 |
| Headache | 10 | 14 |
| Fatigue | 5 | 11 |
| Indigestion | 3 | 9 |
| Dizziness | 4 | 8 |
| Bloating | 5 | 7 |
| Burping | under 1 | 7 |
| Low blood sugar, type 2 diabetes | 2 | 6 |
| Gas | 4 | 6 |
| Gastroenteritis | 4 | 6 |
| Reflux | 3 | 5 |
| Gastritis | 1 | 4 |
| Hair loss | 1 | 3 |
| Altered skin sensation | 1 | 2 |
Label Table 3: 2,116 adults on 2.4 mg and 1,261 on placebo. These are separate trials from the 7.2 mg comparison below [1].
| Side effect | Placebo | Wegovy 2.4 mg | Wegovy 7.2 mg |
|---|---|---|---|
| Nausea | 13 | 35 | 39 |
| Vomiting | 6 | 16 | 22 |
| Altered skin sensation | 0 | 6 | 22 |
| Constipation | 8 | 19 | 20 |
| Abdominal pain | 7 | 9 | 12 |
| Fatigue | 5 | 9 | 11 |
| Headache | 7 | 8 | 9 |
| Dizziness | 1 | 5 | 6 |
| Hair loss | 1 | 3 | 6 |
| Gas | 2 | 2 | 4 |
Label Table 4, Studies 8 and 9: placebo 303 participants, 2.4 mg 304 participants, 7.2 mg 1,311 participants. Includes reactions reported in at least 2% of 7.2 mg participants and more often than in its 2.4 mg and placebo groups. Use these within-trial comparisons; absence from this selected table does not mean an effect never occurred [1].
Gut effects are their own topic. For why they happen and what the label says about each one, see Wegovy and nausea. Tiredness, headache and dizziness get a closer look in does Wegovy make you tired?, and peeing more or feeling thirsty in does Wegovy make you pee more?
Side effects usually start early and return around each dose increase
Wegovy starts at a low weekly dose, and the label raises it gradually over several months before a maintenance dose. The label starts the injection at 0.25 mg a week and allows up to 7.2 mg [1]. Your prescriber decides each dose step.
That slow climb matters for side effects. The label says digestive reactions "were most frequently reported during dosage escalation" [1]. A pooled analysis of the STEP 1 to 3 trials found the same pattern: most stomach events were "transient" and came "during/shortly after dose escalation" [2]. That analysis was written with Novo Nordisk employees among its authors, and Novo Nordisk makes Wegovy.
| Phase | What the trials describe | Source |
|---|---|---|
| First weeks on Wegovy | Stomach effects such as nausea begin; most are mild to moderate | Label §6.1; Wharton 2022 |
| Around each dose increase | Nausea, vomiting and diarrhea were reported most often during escalation | Label §6.1 |
| On a steady maintenance dose | Stomach effects were described as transient; maintenance was "well tolerated" in STEP 4 | Wharton 2022 |
| Any time | Pancreatitis, gallbladder disease and allergic reactions can occur; frequency varies by event | Label §5 |
The full pooled analysis reports episode-duration medians, which cannot predict an individual’s symptoms. Constipation can last longer than nausea, vomiting or diarrhea.
For most people the stomach effects ease, but not for everyone
In the STEP 1 to 3 trials, 98.1% of digestive events on semaglutide were mild to moderate and 99.5% were non-serious [2]. Still, 4.3% of people on Wegovy injection stopped treatment because of a digestive side effect, against 0.7% on placebo [1].
Across all side effects, 6.8% of people on Wegovy 2.4 mg stopped for good, against 3.2% on placebo. Nausea (1.8%), vomiting (1.2%) and diarrhea (0.7%) were the most common reasons [1]. In the large heart-outcomes trial, which ran for about three years, 16% stopped because of an adverse event, against 8% on placebo [1].
The label also discusses hair loss. The label ties it to weight reduction: 3.3% on Wegovy 2.4 mg against 1% on placebo, and 4% of women. At 7.2 mg it was 5.8%, and 8.4% of women [1].
The 7.2 mg dose adds more skin-sensation side effects
Wegovy HD, the 7.2 mg dose, had similar stomach numbers to 2.4 mg but much more dysesthesia: tingling, burning or unusually sensitive skin. It affected 22% of people at 7.2 mg, against 6% at 2.4 mg in the same trials [1]. Among people who had it at 7.2 mg, 18% did not report recovering during the trial.
The Wegovy pill (25 mg daily) produced side effects "similar to those listed in Table 3" in its trial, with dysesthesia in 5% and none on placebo [1]. For how the pill differs from the shot, see oral semaglutide.
Warnings and serious risks are described in the label
Frequency differs by risk and population, and some reports have no known rate. Each rate below is from the label's adult trials unless noted.
| Risk | Wegovy vs placebo | Signs the label lists | Label section |
|---|---|---|---|
| Acute pancreatitis | 0.2 vs under 0.1 cases per 100 patient-years | Persistent or severe belly pain, sometimes into the back, with or without vomiting | 5.2 |
| Gallstones (cholelithiasis) | 1.6% vs 0.7% | Upper belly pain, fever, yellow skin or eyes, clay-colored stools | 5.3 |
| Gallbladder inflammation (cholecystitis) | 0.6% vs 0.2% | Same as above | 5.3 |
| Acute kidney injury | 0.4 vs 0.2 cases per 100 patient-years | Often after vomiting or diarrhea with dehydration | 5.5 |
| Severe digestive reactions | 4.1% vs 0.9% | Stomach problems that are severe or won't go away | 5.6 |
| Serious allergic reactions | Reported; rate not given | Swelling of face, lips, tongue or throat; severe rash or itching; very fast heartbeat | 5.7 |
| Low blood sugar, type 2 diabetes | 6.2% vs 2.5% | Shakiness, sweating, confusion, fast heartbeat; higher risk with insulin or sulfonylureas | 5.4 |
| Eye complications, type 2 diabetes | 4% vs 2.7% diabetic retinopathy (Study 3) | Changes in vision | 5.8 |
| Faster resting heart rate | Average rise of 1 to 4 beats per minute | Racing or pounding heartbeat at rest | 5.9 |
| Low blood pressure and fainting | 1.3% vs 0.4%; fainting 0.8% vs 0.2% | Dizziness, lightheadedness, fainting | 6.1 |
| Food in the lungs under anesthesia | Rare postmarketing reports | Tell every surgeon and anesthetist you take Wegovy | 5.10 |
Wegovy prescribing information, DailyMed version 19, June 2026. Patient-year rates count events per 100 years of combined treatment time.
Two more appear under "other" reactions. In the heart-outcomes trial, women had more hip and pelvis fractures on Wegovy (1% vs 0.2%), as did people 75 and older (2.4% vs 0.6%). Kidney stones were reported by 1.2% vs 0.8% [1]. For gallbladder problems in depth, see Wegovy and your gallbladder.
The boxed warning is about thyroid tumors seen in rodents
In rodents, semaglutide causes dose-dependent and treatment-duration-dependent thyroid C-cell tumors at clinically relevant exposures. It is unknown whether WEGOVY causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans as human relevance of semaglutide-induced rodent thyroid C-cell tumors has not been determined.[1]
Because of that warning, Wegovy is not for anyone with a personal or family history of medullary thyroid cancer or the inherited condition MEN 2. The label asks you to report a lump in the neck, hoarseness, trouble swallowing or shortness of breath [1]. The human evidence is covered in Wegovy and thyroid cancer, and who should not take Wegovy at all in is Wegovy safe?
Severe belly pain, vomiting you can't keep down, or swelling of the face need prompt care
The label and its Medication Guide name the symptoms that should not wait for your next visit [1]:
- Stop Wegovy and call your prescriber now for severe stomach pain that won't go away, with or without vomiting, sometimes felt in the back (possible pancreatitis).
- Get emergency help for swelling of the face, lips, tongue or throat, trouble breathing or swallowing, a severe rash or itching, fainting, or a very rapid heartbeat (possible serious allergic reaction).
- Call your prescriber for nausea, vomiting or diarrhea that doesn't stop, since fluid loss can injure the kidneys.
- Call your prescriber for upper belly pain with fever, yellowing skin or eyes, or clay-colored stools (possible gallbladder problem).
- Tell your prescriber about a racing heartbeat at rest, changes in vision if you have type 2 diabetes, or a lump in your neck.
- Before any surgery or sedation, tell the team you take Wegovy.
Your prescriber decides how to handle side effects
What happens next is a medical decision, not a home fix. Your prescriber decides the dose steps, and whether to slow them, pause or stop. Don't change your dose on your own. Tell them which symptom you have, how long it has lasted, and whether you can keep fluids down.
If you use compounded semaglutide instead, the label above still describes the drug, but not the product. Compounded semaglutide is not FDA-approved, and FDA does not check its safety, effectiveness or quality before it ships [3]. See is compounded semaglutide safe? To see how a related drug compares, read tirzepatide side effects; for Wegovy's sister brand, see is Ozempic safe? The molecule itself is covered in our semaglutide guide.