All you need to know about Wegovy side effects

Wegovy (semaglutide) is an injectable weight-loss medication that’s proven effective when used alongside a reduced-calorie diet and increased physical activity. In clinical trials, participants taking Wegovy lost up to 14.9% of their body weight or more in 68 weeks.

If you’re considering a Wegovy online prescription for weight management or weight loss, it’s a good idea to know what to expect while taking this medication. In this blog, you’ll learn more about Wegovy side effects and how to manage them.

If you have questions about Wegovy or its side effects, speak to a healthcare professional. Find a provider on Klarity Health today for Wegovy and other weight loss treatments.

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What to know about Wegovy before using it

FDA approval & eligibility​

Wegovy (semaglutide) is a prescription weight-loss medication made by Novo Nordisk. It is U.S. Food and Drug Administration (FDA)-approved for:

• Adults with obesity (BMI ≥30) or overweight (BMI ≥27) accompanied by weight-related conditions such as high blood pressure, type 2 diabetes, or heart disease.
• Adults with heart disease who are either obese or are medically overweight to reduce the risk of major cardiovascular events, including heart attack, stroke, or death.
• Adolescents aged 12+ with a BMI in the 95th percentile for their age and sex.

Note: 

As a GLP-1 receptor agonist medication, Wegovy mimics glucagon-like peptide-1 (GLP-1), a hormone in your body that’s released after eating to lower your blood sugar and delay stomach emptying. These effects help to decrease appetite, so you eat less and potentially lose weight.  

It should be used alongside a reduced-calorie diet and increased physical activity under medical supervision.

Boxed warning​

Wegovy carries the FDA’s strongest ​boxed warning​ for thyroid tumors, including medullary thyroid cancer. Animal studies showed increased thyroid cancer risk with semaglutide (the active ingredient in Wegovy), but human cases remain unconfirmed. If you have a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2 (MEN 2), discuss taking Wegovy and your options with your healthcare provider.

Why Wegovy side effects occur

Side effects are the unwanted symptoms you could have when taking medication. While subcutaneous weight loss injections like Wegovy are considered safe, they may cause side effects. 

Wegovy’s effects on digestion and appetite regulation explain most side effects:

• ​Delayed gastric emptying causes nausea, bloating, and vomiting.
• ​Central appetite suppression may lead to temporary hypoglycemia or fatigue.
• ​Dose adjustments during treatment often trigger transient gastrointestinal (GI) distress.

Most symptoms resolve as the body adapts, typically within 2 weeks.

Common Wegovy side effects

Common Wegovy side effects are those seen in up to 10% of participants. If seen in more than 10% of participants, the side effect is considered very common. In clinical trials for Wegovy, about 2 in 5 participants experienced common side effects. 

The table below shows the percentage of clinical trial participants who experienced the 5 most common side effects of Wegovy. 

Other common Wegovy side effects include: 

• Abdominal distension (swelling)
• Abdominal pain
• Belching
• Dizziness
• Dysesthesia (abnormal sensation)
• Dyspepsia
• Headache
• Fatigue
• Flatulence
• Gastritis (inflammation of the stomach)
• Gastroenteritis (inflammation of the digestive tract)
• Gastroesophageal reflux disease (GERD)
• Hair loss
• Hypoglycemia (low blood sugar)
• Nasopharyngitis (inflammation of the nose and throat)

Though the list of possible side effects looks worrisome, most people don’t experience them. Side effects were the most common reason for people to drop out of the trial. Gastrointestinal (GI) side effects were experienced by 73% of participants taking Wegovy, compared to 47% of those taking a placebo. Likewise, 4.3% of people taking Wegovy had serious digestive system problems compared to 0.9% of those taking the placebo. 

During one clinical trial, 84% of people taking Wegovy completed the trial. The remainder (16%) dropped out of the trial because of side effects,  but so did 8% of those taking a placebo. 

How to manage common side effects of Wegovy

If you experience side effects from Wegovy or another weight loss medication, you may be able to manage them with diet and lifestyle changes. Here are some things you can try to reduce the common side effects of Wegovy. 

• Drink plenty of water and fluids. Staying hydrated can improve the function of your digestive and cardiovascular systems, which may relieve headaches and GI side effects like indigestion, constipation, and diarrhea. 
• Eat small, regular meals. Your body can digest small meals more easily, which can reduce your chances of having indigestion, constipation, and heartburn. Eating regularly can reduce your risk of low blood sugar.  
• Avoid lying down immediately after meals. Instead, take a short walk or stay active in other ways to help your digestive system move food through your system.
• Suck on ice chips or try ginger chews to relieve nausea. 
• Avoid caffeinated drinks, like coffee, if you’re having diarrhea. Instead, stay hydrated with fluids like water, soups, broth, and vegetable juices. 
• Add fiber to your diet. Aim for 25 to 30 grams of fiber a day. To do this, eat high-fiber foods, such as fruits, vegetables, whole grains, and legumes. Eating bananas, oats,  brown rice, and beans is a good place to start. 
• Avoid fatty, fried, or spicy food. These foods can worsen GI symptoms like heartburn, indigestion, and gas. To potentially reduce vomiting, choose bland, baked, or low-fat food options. 
• Exercise regularly. Apart from helping you lose weight, exercise supports your digestive system. Aim for 150-300 minutes of vigorous movement a week to reduce your chances of constipation and indigestion.
• Get enough sleep. Doing this every day helps reduce any tiredness you are feeling while it gives your gut time to rest and heal. Aim for at least 7 hours a day and stick to a routine sleep schedule.
• Avoid alcohol. Alcohol can worsen digestive system side effects and increase your risk of low blood sugar. If you decide to drink alcohol while taking Wegovy, make sure it’s not on an empty stomach or immediately after exercise to reduce the risk of side effects.
• Use over-the-counter (OTC) medication. OTC medications can offer relief for specific side effects. For example:

Wegovy may not be the best medicine for you if your side effects persist despite treatment and lifestyle changes. Talk to your healthcare provider about your options. They’ll help you decide whether to stop Wegovy, lower your dose, or try other Wegovy alternatives. 

What are the worst side effects of Wegovy?

Serious side effects can occur when taking Wegovy. Serious side effects experienced in clinical trials include:

• Serious allergic reactions, such as swelling of your face, lips, tongue or throat, trouble breathing or swallowing, a severe rash,  itching, fainting, feeling faint, dizziness or a very rapid heartbeat.
• Low blood sugar, especially if you have type 2 diabetes. Symptoms include feeling light-headed, sweating, dizziness, giddiness, feeling confused or drowsy, headache, blurry vision, slurred speech, shakiness, fast heartbeat, anxiety, irritability or mood changes, hunger, weakness, or feeling jittery.
• Kidney damage, including acute kidney injury or kidney failure.
• Gallbladder problems, including acute gallbladder disease and gallstones. Symptoms include pain in your upper abdomen, fever, yellowing of your skin or eyes, or clay-colored stools. 
• Pancreatitis (inflammation of the pancreas), which is characterized by persistent pain in your upper abdomen, especially pain that radiates from your stomach to your back. Pancreatitis can occur with or without vomiting.
• Rapid heartbeat, greater than 100 beats per minute. 
• Vision changes and/or diabetic retinopathy, if you have type 2 diabetes.
• Depression or suicidal thoughts, including low mood and associated changes in behavior.
• Ileus, or inability of the intestines to contract normally, can prevent your body from properly emptying food waste.

Other rare side effects seen in clinical trials are 

• Reactions at the injection site such as swelling, pain, and redness
• Persistent foul, rancid, metallic taste in the mouth
• Fractures which are more common in older adults taking Wegovy
• Low blood pressure and fainting 
• Hiccups
• Hemorrhoids
• Appendicitis 
• Inflammation of the nose and throat
  

If you experience low blood sugar, consume a sugary drink or meal as soon as possible. For other serious side effects, contact your healthcare provider or call 911 immediately. 

What are the long-term effects of using Wegovy?

The long-term side effects of using Wegovy can be both good and bad. Many users maintain significant weight loss over time. This can improve overall health, reduce the risk of heart disease, improve metabolic markers and type 2 diabetes, lower cholesterol levels and blood pressure, and otherwise improve obesity-related conditions.

But the news isn’t all good. Rapid weight loss from any method, including Wegovy, can increase the risk of gallstones or gallbladder disease. And while it’s rare, using Wegovy over time may increase the risk for pancreatitis, or worsen kidney function in some cases.

Regular monitoring by your healthcare provider is important to manage any risks associated with long-term use because the evidence still isn’t all in for any of the GLP-1 agonist medications.

Who shouldn’t take Wegovy?

Wegovy may not be appropriate for everyone. Avoid using this medication if any of the following apply to you:

If you are taking these medications

Wegovy may interact with other drugs, potentially reducing their efficacy or increasing risks. Use extra caution if you’re currently using:

• Insulin and other diabetes medications: Wegovy lowers blood sugar and so does insulin, sulfonylureas, and metformin. Let your care team know if you take diabetic medications that lower your blood sugar so they can adjust your dose of Wegovy accordingly. 
• Oral medications: GLP-1 agonists like Wegovy delay stomach emptying which can cause pills to stay in your stomach longer. Wegovy didn’t hinder the absorption of oral medications in clinical trials. But, it’s a good idea to let your healthcare provider know about any oral medications you’re taking, including OTC drugs. 

Medical conditions

Avoid Wegovy if you:

• Are pregnant, breastfeeding, or planning to become pregnant. Wegovy hasn’t been studied in pregnant or breastfeeding women so its safety in these populations isn’t known. 
• Have a personal or family history of thyroid cancers. In animal studies, Wegovy increased the risk of such cancers. While this hasn’t been observed in humans, it’s better to avoid Wegovy if you have an increased risk of developing these cancers.
• Are allergic to semaglutide or another ingredient in Wegovy. This includes if you’ve had an allergic reaction to these ingredients previously.
• Experience severe digestive system disorders. Wegovy delays gastric emptying which may affect individuals with severe digestive system disorders, such as inflammatory bowel disease (IBD).
• Are below 12 years of age. Wegovy hasn’t been studied in children younger than 12, so experts don’t know if it’s safe for that age group. 
• Have kidney, gallbladder, or pancreas problems. Wegovy may contribute to or worsen these problems. 
• Have type 1 diabetes or a history of diabetic retinopathy.

Wegovy vs. other GLP-1 agonists: Side effect comparison

Wegovy, Ozempic (semaglutide), and Zepbound (tirzepatide) are GLP-1 agonists but differ in side effects.

Wegovy vs Ozempic side effects

Wegovy and Ozempic contain the same medicine (semaglutide) but Wegovy uses a higher weekly dose (2.4 mg vs 1 mg). More people using Wegovy report gastrointestinal issues (73%) compared to Ozempic users (36%). Gastrointestinal issues include nausea, diarrhea, and stomach pain. About 5% to 10% Wegovy users stop treatment due to severe stomach issues, while only 4% of Ozempic users do. 

Zepbound vs Wegovy side effects

Zepbound and Wegovy are FDA-approved for weight loss.  They cause common side effects like nausea, vomiting, and diarrhea. But Zepbound works differently with Wegovy. Zepbound works on two body systems (GIP + GLP-1) compared to Wegovy’s single system (GLP-1). Zepbound’s nausea rate (up to 29%) is lower than Wegovy’s (44%), while vomiting rates also show a difference (up to 13% for Zepbound vs 24% for Wegovy).

Patient experiences with Wegovy side effects

Real Wegovy users often share their experiences in reviews and online chat groups. Mild side effects like nausea, vomiting, and constipation are the leading concerns among Wegovy reviews. Yet a number of reviewers say they don’t experience side effects. Most agree that there’s no way to know what form your side effects will take until you start taking Wegovy. 

People have also complained of changes in the way their face, neck, and buttocks look after taking Wegovy for a while. The changes in appearance are due to skin sagging after losing weight too fast. If you’re concerned about this, talk to your healthcare provider.

What to tell your healthcare provider before using Wegovy 

One of the best ways to avoid serious side effects of Wegovy is to have an open discussion with a healthcare professional. Choose a PharmD (doctor of pharmacy, aka pharmacist) who understands the side effects of Wegovy well, or whichever healthcare professional treats you for obesity or related health conditions right now. They can give you an honest opinion based on your situation and share all of the benefits and risks of taking Wegovy.

Remember, each piece of your medical history is important for your healthcare provider to know. They also need to understand your goals for using Wegovy and weight loss generally. This way they have the best opportunity to share tips for managing the side effects of Wegovy that are most likely to help you.

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Key takeaway

Wegovy (semaglutide) is a prescription weight loss medication that should be used as part of a medical weight loss program. Like any medication, it can cause side effects. Mild or moderate side effects usually improve or resolve within a few weeks of starting Wegovy or increasing your dose. They can often be managed with lifestyle and dietary adjustments and/or taking OTC remedies. 

Wegovy may cause serious side effects that can be life-threatening. If you experience serious side effects, contact your healthcare provider or call 911 immediately. 

Communicate with your healthcare provider about your experience. And keep your follow-up appointments while taking Wegovy, so your provider can track your progress and symptoms. 

Find out if Wegovy is right for you

Find a weight loss provider on Klarity Health who can help you decide if Wegovy is the right weight loss medication for you. Appointments are available in as little as 24 hours.* You never need insurance. And you won’t pay hidden fees.