Wegovy side effects: common vs serious risks
Wegovy side effects are often stomach related, but some can be serious. See common vs urgent symptoms, what may help, and when to call.
Key facts
- Semaglutide + B12 is $157/month (billed $157 every 4 weeks), charged only after a clinician approves it.
- Answer a few health questions online. A licensed clinician reviews them. If approved, it ships to your door.
- Adults 18 or older. A licensed clinician reviews your health history and decides whether treatment is appropriate for you. Availability depends on the state you live in.
If you searched wegovy side effects, you are usually trying to separate expected stomach symptoms from warning signs that need medical attention. Wegovy (semaglutide) can cause common digestive side effects, but it also has uncommon risks that are important to recognize. This guide summarizes what the FDA prescribing information and Medication Guide say about common and serious Wegovy side effects, what may help, and when to call a clinician.
- Wegovy side effects are most often nausea, vomiting, diarrhea, constipation, and stomach pain.
- Side effects are more likely when starting or increasing the dose and may improve over time.
- Get urgent care for severe belly pain, dehydration, allergic reaction symptoms, or severe low blood sugar symptoms.
- Wegovy has a boxed warning about thyroid C-cell tumors and is not for people with MTC or MEN 2.
What are Wegovy side effects?
Most common symptoms
The most common Wegovy side effects are gastrointestinal, meaning they affect your stomach and intestines. These include nausea, vomiting, diarrhea, constipation, and abdominal pain. They are more likely when starting treatment or after a dose increase.
Other common effects
Wegovy can also cause decreased appetite, indigestion (dyspepsia), burping, bloating, gas, heartburn (GERD), headache, dizziness, fatigue, and injection site reactions. Some symptoms can overlap with not eating or drinking enough while you adjust.
Serious risks to know
Serious side effects are less common but can include pancreatitis, gallbladder problems, kidney problems (often related to dehydration), severe allergic reactions, and low blood sugar when used with certain diabetes medicines. Wegovy also carries a boxed warning about thyroid C-cell tumors.
Common and serious side effects (and what to do about them)
Nausea and vomiting
Nausea is one of the most common Wegovy side effects, and vomiting can occur. It is often worse after dose increases and may improve as your body adjusts. If you cannot keep fluids down or you feel faint, contact a clinician because dehydration can become dangerous.
Diarrhea or constipation
Diarrhea and constipation are both common with Wegovy. Either can contribute to dehydration, dizziness, or weakness if you are not replacing fluids. If symptoms are severe, persistent, or you notice blood in stool, contact a clinician promptly.
Stomach pain and indigestion
Abdominal pain, bloating, gas, and indigestion can occur, especially early in treatment. Mild discomfort can be expected, but severe or persistent pain is not something to ignore. Severe upper abdominal pain that may spread to your back can be a warning sign for pancreatitis.
Pancreatitis
Pancreatitis is inflammation of the pancreas and is a serious risk listed for Wegovy. Seek urgent medical evaluation for severe abdominal pain that does not go away, with or without vomiting. Your clinician may evaluate other causes and decide whether Wegovy should be continued.
Gallbladder problems
Wegovy can increase the risk of gallbladder disease, including gallstones (cholelithiasis) and gallbladder inflammation (cholecystitis). Call a clinician urgently for right upper belly pain, fever, or yellowing of the skin or eyes. These symptoms may need prompt evaluation.
Kidney problems from dehydration
Kidney injury has been reported, sometimes in people who had nausea, vomiting, or diarrhea leading to dehydration. Get medical help if you have very little urine, swelling, or worsening fatigue, especially if you cannot keep fluids down. A clinician may check kidney function and hydration status.
Low blood sugar
Wegovy can cause low blood sugar (hypoglycemia), and the risk is higher if you use insulin or a sulfonylurea. Symptoms can include sweating, shakiness, fast heartbeat, confusion, or feeling faint. Ask your prescriber what to watch for and when to seek help if you take diabetes medicines.
Thyroid tumor warning
Wegovy has a boxed warning because semaglutide caused thyroid C-cell tumors in rodents, and it is unknown whether this risk applies to humans. Contact a clinician if you notice a neck lump, hoarseness, trouble swallowing, or shortness of breath. Wegovy should not be used if you or a family member has medullary thyroid carcinoma or if you have MEN 2.
Allergic reactions
Serious hypersensitivity reactions, including anaphylaxis and angioedema, have been reported with semaglutide. Seek emergency care for swelling of the face, lips, tongue, or throat, trouble breathing, or widespread hives. Tell your clinician about any prior reactions to GLP-1 medicines.
Increased heart rate
Wegovy can increase heart rate. If you notice a racing heartbeat, palpitations, chest discomfort, or you feel lightheaded, contact a clinician. They can review other causes and whether the medication may be contributing.
Mood changes
The prescribing information advises monitoring for depression or suicidal thoughts or behavior. If you or people close to you notice new or worsening depression, unusual mood changes, or thoughts of self harm, contact a clinician right away. If you are in immediate danger, seek emergency help.
Side effects in women
In general, the labeled side effects are the same for women and men. What can differ is how symptoms feel day to day, especially nausea, constipation, or gallbladder type pain. If you are pregnant, planning pregnancy, or breastfeeding, discuss risks and alternatives with a clinician.
When to call a clinician or seek urgent care
| If you notice | Why it matters | What to do |
|---|---|---|
| Severe belly pain that will not go away, with or without vomiting | Possible pancreatitis | Seek urgent medical evaluation |
| Right upper belly pain, fever, yellow skin or eyes | Possible gallbladder problem | Call a clinician urgently or seek urgent care |
| Unable to keep fluids down, fainting, very little urine | Dehydration and possible kidney injury | Seek same day medical care |
| Swelling of face or throat, trouble breathing, widespread hives | Possible severe allergic reaction | Call emergency services |
| Shakiness, sweating, confusion, fast heartbeat | Possible low blood sugar, especially with insulin or sulfonylureas | Follow your diabetes plan and contact a clinician |
| Neck lump, hoarseness, trouble swallowing | Possible thyroid issue that needs evaluation | Schedule prompt medical assessment |
Practical tips that often help
Eat smaller, slower meals
Large meals can worsen nausea and reflux. Smaller portions and slower eating may be easier to tolerate.
Prioritize fluids
Sip fluids through the day, especially with vomiting or diarrhea. Dehydration can worsen dizziness and kidney risk.
Avoid greasy, very sweet foods
High fat and very sweet foods can trigger nausea, heartburn, and diarrhea for some people.
Track patterns
Note when symptoms happen relative to meals and dose changes. This helps your clinician decide what to do next.
Review other medicines
Wegovy slows stomach emptying, which can affect some oral medicines. Review your medication list with a clinician.
Frequently Asked Questions
What are the side effects of Wegovy?
The most common Wegovy side effects are nausea, vomiting, diarrhea, constipation, and abdominal pain. Serious risks can include pancreatitis, gallbladder disease, kidney problems related to dehydration, allergic reactions, and low blood sugar (especially with certain diabetes medicines).
What are the side effects of Wegovy (wegovy side effects) most people notice first?
Most people notice stomach and bowel symptoms first, such as nausea, constipation, diarrhea, or vomiting. These are more likely when starting Wegovy or after a dose increase. If symptoms are severe or you cannot keep fluids down, contact a clinician.
Are there Wegovy side effects in females that are different?
The FDA labeled side effects are generally the same in females and males. What can differ is how symptoms feel day to day, especially nausea, constipation, or gallbladder type pain. If you are pregnant, planning pregnancy, or breastfeeding, discuss safety with a clinician.
Does Wegovy cause cancer?
Wegovy has a boxed warning because semaglutide caused thyroid C-cell tumors in rodents, and it is unknown whether this risk applies to humans. Wegovy should not be used if you or a family member has medullary thyroid carcinoma or if you have MEN 2. Report neck lumps, hoarseness, or trouble swallowing to a clinician.
Can missing a dose cause Wegovy side effects?
Missing a dose does not typically cause withdrawal symptoms, but restarting after a gap can sometimes bring back nausea or other stomach side effects. The prescribing information includes guidance on missed doses and when to contact your prescriber for next steps. If you feel unwell after a missed dose, check in with a clinician.