All you need to know about Wegovy side effects — from common to uncommon

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 to learn more about Wegovy and its side effects. 

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What to know about Wegovy before using it

Wegovy (semaglutide) is a prescription weight-loss medication made by Novo Nordisk. It’s U.S. Food and Drug Administration (FDA)-approved for adults with obesity (a body mass index [BMI] of 30 or more) or overweight (a BMI of 27 or more) with a weight-related medical condition. This includes high blood pressure, type 2 diabetes, or heart disease

It’s also approved to reduce the risk of major cardiovascular events, such as death, heart attack, or stroke, in adults with diagnosed heart disease and who have either obesity or are medically overweight.

Wegovy is FDA-approved for adolescents aged 12 and older with a BMI in the 95th percentile for their sex and age too. (This is one of the important differences between Wegovy and Ozempic, which both contain the active ingredient semaglutide. Ozempic is not FDA-approved for children, and should only be used by adults with type 2 diabetes to lower blood sugar.)

Wegovy is among the GLP-1 receptor agonist medications. This class of drugs 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. 

Wegovy is meant for medically-supervised weight loss and should be paired with a reduced-calorie diet and increased physical activity for best results. 

Like any medication, it can cause common and serious side effects. Some people should avoid it and no one should use it without medical supervision.

Understanding Wegovy side effects

Side effects are the unwanted symptoms you could have when taking medication. While subcutaneous weight loss injections like Wegovy are considered safe, they can cause side effects that vary from pesky inconveniences to more serious issues. 

Common 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. Common side effects tend to be mild or moderate in nature and can often be managed by lifestyle changes.

Serious side effects, such as low blood sugar, allergic reactions, and pancreatitis, are possible. In clinical trials, these side effects affected less than 2% of participants. 

Your Wegovy experience will be unique. You may not experience side effects and if you do, they may not affect you the same way they affect other people. Also, medications like Wegovy can interact with other drugs, so be sure to discuss any other medications you’re taking with your healthcare provider before you start Wegovy. 

Wegovy isn’t suitable for everyone. Factors like your medical history and current health conditions affect whether Wegovy’s benefits outweigh the risks in your case. Speak with a provider before starting a weight-loss medication to ensure it’s right for you.  

Common Wegovy 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. 

You’re more likely to experience side effects when you start taking Wegovy or when your dosage is increased. Most side effects are mild or moderate and usually go away after a week or two. Reach out to your provider if symptoms persist or interfere with your daily activities. 

How to reduce the 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 another weight loss drug. 

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 a healthcare professional.

Are there serious 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, rapid heart rate, 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 light-headedness, 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 stomach pain that radiates toward 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 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 side effects of Wegovy that are most likely to help you.

Drug interactions to know about with Wegovy

Wegovy can interact with other drugs. Interactions may increase or decrease a medication’s effectiveness or cause side effects. Possible Wegovy drug interactions include: 

• 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. 

Boxed warning for Wegovy

Wegovy has a boxed warning for thyroid tumors and cancers such as medullary thyroid carcinoma. A boxed warning is the most serious warning from the FDA. It alerts doctors, patients, and the public about possible dangerous drug effects.

In animal studies of semaglutide (the active ingredient in Wegovy) there was a higher risk of thyroid cancer. However, thyroid cancer hasn’t been tied to Wegovy in humans. Since animal studies don’t always predict what happens in humans, it’s not certain whether Wegovy can increase thyroid cancer risk in humans. 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. 

Who shouldn’t take Wegovy?

Wegovy isn’t suitable for everyone. You should 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.

Reasons why you might feel bad on semaglutide 

Most people feel better after losing weight with medications that contain semaglutide. But taking them isn’t always easy for everyone, because the side effects themselves can make you feel bad.

This might only be true when you first start taking semaglutide, but sometimes side effects like nausea, gas, burping, vomiting, or abdominal pain last.

And for some people, a lack of appetite can be a problem. Not wanting to eat can cause them social embarrassment, or make them feel weak, fatigued, and generally unwell.

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.

What happens when you stop Wegovy?

When you stop taking Wegovy, you may gain some weight back, because its appetite-suppressing effects wear off. Your food cravings usually increase or come back, so it may be harder to maintain your weight loss.

If you’re using Wegovy off-label to also help manage type 2 diabetes, stopping it can cause your blood sugar levels to rise. You may also see some of the other benefits of taking it, like lower blood pressure and cholesterol levels, slip over time. You can help minimize this by keeping up with lifestyle changes like continuing to exercise and eating a healthy diet.

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.