The 10 most common Wegovy side effects and how long they last

If you’ve thought about starting the Wegovy® injection for weight loss, you’ve probably heard about the side effects. Nausea, diarrhea, constipation, and other stomach issues are common with GLP-1 medications, particularly when you first start treatment or increase your dose.

Why do they happen? Wegovy®’s active ingredient, semaglutide, mimics the hormone GLP-1 to reduce appetite, slow digestion, and help regulate blood sugar. While these actions can help you lose weight, those same effects can also leave you feeling queasy, constipated, or uncomfortable after eating.

But side effects don’t happen to everyone, and some are much more common than others. So, how likely are you to experience each one? What might it actually feel like day to day? And what can you do if it happens to you?

Let’s look at the 10 most common side effects of the Wegovy® injection based on clinical trial data, including how often they occurred, why they may happen, and what can help make them more manageable. Knowing what to expect can make it easier to recognize what’s normal, prepare for potential side effects, and know when something deserves a call to your doctor.

The 10 most common Wegovy® side effects

Most of the common side effects of the Wegovy® injection involve your stomach and digestive system. That makes sense based on how semaglutide works. It reduces appetite and ⁠slows how quickly food leaves your stomach, which can contribute to nausea, feeling overly full, constipation, and other digestive symptoms.

The percentages below come from ⁠studies of adults taking the Wegovy® injection at the recommended 2.4 mg maintenance dose. Side effects can be different for everyone, and they may come and go as your dose increases.

1. Nausea (44%)

Nausea is the most common side effect of the Wegovy® injection, ⁠affecting about 44% of adults in clinical trials. It’s especially common while your dose is being increased, which is one reason Wegovy® starts at a low dose and gradually works up to the maintenance dose.

• What you might experience: You might feel queasy, overly full, or like you don’t want to eat much. Nausea may be more noticeable after eating, particularly if you eat a large or rich meal.
• How long will it last? About 8 days. Nausea usually doesn’t last forever. In ⁠research involving more than 2,000 people taking semaglutide 2.4 mg, episodes typically lasted about eight days. Nausea was most common while doses were being increased and became less common as treatment continued.
• What might help: ⁠GLP-1 experts recommend eating smaller meals, eating slowly, and avoiding greasy or rich foods if they make nausea worse. Sip fluids throughout the day to stay hydrated. If nausea becomes difficult to manage, talk to your prescriber about whether slowing your dose increase might help.

2. Diarrhea (30%)

Diarrhea is the second most common Wegovy® side effect, ⁠affecting about 30% of adults in clinical trials. Like nausea, it tends to be more common early in treatment and while your dose is increasing.

• What you might experience: You may have loose or watery stools, need to use the bathroom more frequently, or experience some cramping. The main thing to watch for is dehydration, especially if you’re also vomiting.
• How long will it last? About 3 days. Diarrhea tends to be one of the shorter-lived Wegovy® side effects. In ⁠research on people taking semaglutide 2.4 mg, episodes typically lasted about three days.
• What might help: ⁠GLP-1 guidance recommends drinking plenty of fluids and temporarily limiting foods or drinks that make diarrhea worse, which may include fatty foods, alcohol, or coffee. Contact your healthcare provider if diarrhea is severe, persistent, or makes it difficult to stay hydrated.

3. Vomiting (24%)

Vomiting ⁠affected about 24% of adults taking Wegovy® in clinical trials. Like nausea, it tends to happen more often while your dose is being increased.

• What you might experience: Vomiting may happen along with nausea or stomach discomfort. A single episode may pass quickly, but repeated vomiting can lead to dehydration and, in more serious cases, kidney problems.
• How long will it last? About 2 days. Vomiting tends to be short-lived. In ⁠research on people taking semaglutide 2.4 mg, episodes typically lasted about two days.
• What might help: Focus on hydration, taking small sips if drinking a lot at once is difficult. ⁠GLP-1 guidance also recommends eating smaller amounts once you’re ready to eat again. Contact your healthcare provider if you’re vomiting repeatedly or can’t keep fluids down.

4. Constipation (24%)

Constipation ⁠affects about 24% of adults taking the Wegovy® injection, but it can behave differently from nausea, diarrhea, and vomiting because it tends to stick around longer.

• What you might experience: You may have fewer bowel movements, harder stools, or feel like you can’t completely empty your bowels.
• How long will it last? About 47 days. Constipation can last considerably longer than other digestive side effects. In ⁠research on people taking semaglutide 2.4 mg, episodes typically lasted about 47 days. That doesn’t mean everyone will be constipated for weeks, but it helps explain why this side effect can feel more persistent.
• What might help: Gradually increase fiber, drink plenty of fluids, and stay active. These strategies are recommended in ⁠GLP-1 guidance as well as for constipation in general. If they aren’t enough, ask your healthcare provider whether an over-the-counter option might help.

Noom’s ⁠guide to Wegovy® constipation has more ways to manage this side effect.

5. Abdominal pain (20%)

About ⁠20% of adults taking Wegovy® reported stomach pain in clinical trials. This can include pain or discomfort anywhere in the stomach area.

• What you might experience: You might notice mild cramping, aching, or general stomach discomfort, particularly alongside nausea, constipation, or bloating.
• How long will it last? There’s no set timeline. Research hasn’t established a typical duration for stomach pain with Wegovy®. Mild discomfort may come and go, but pain that is severe, persistent, or getting worse shouldn’t simply be written off as a normal side effect.
• What might help: There isn’t a specific treatment for mild Wegovy®-related stomach pain, but general GLP-1 advice like eating smaller meals, stopping when you feel full, and avoiding foods that trigger discomfort may help.

⁠Severe stomach pain that doesn’t go away, especially if it spreads to your back, can be a sign of pancreatitis and needs medical attention.

6. Headache (14%)

Headaches were ⁠reported by about 14% of adults taking Wegovy® in clinical trials. Unlike most of the side effects higher on this list, headaches aren’t a digestive symptom.

• What you might experience: You might notice a mild or moderate headache. Dehydration from vomiting or diarrhea could contribute, and if you have diabetes and take certain medications, a headache can sometimes be a sign of low blood sugar.
• How long will it last? There’s no set timeline. Research hasn’t established how long Wegovy®-related headaches typically last. If a headache is persistent, keeps returning, or feels different from headaches you normally get, talk to your healthcare provider.
• What might help: There isn’t a Wegovy®-specific treatment for headaches. Staying hydrated and making sure your lower appetite isn’t causing you to regularly skip meals may help. If you have diabetes, check your blood sugar if a headache comes with symptoms such as shakiness, sweating, or dizziness.

7. Fatigue (11%)

About ⁠11% of adults reported fatigue while taking Wegovy® in clinical trials. Feeling tired can have many causes, so Wegovy® may not always be the only thing contributing.

• What you might experience: You may feel more tired or have less energy than usual. Eating much less than you did before starting Wegovy® or becoming dehydrated because of digestive side effects may contribute.
• How long will it last? There’s no set timeline. Studies haven’t established how long Wegovy®-related fatigue typically lasts. If your energy doesn’t improve as you adjust to treatment—or fatigue gets worse—it’s worth checking in with your healthcare provider rather than assuming you need to push through it.
• What might help: Make sure you’re still getting enough food and fluids even if your appetite is lower. Protein and other nutrient-rich foods, hydration, sleep, and regular movement can support your energy, although these are general health strategies rather than treatments specifically studied for Wegovy® fatigue.

8. Indigestion (9%)

Indigestion ⁠affected about 9% of adults taking Wegovy® in clinical trials. You may also hear your doctor call this dyspepsia, but it simply means discomfort in the upper part of your stomach.

• What you might experience: You may feel overly full, uncomfortable, bloated, or have a burning feeling after eating. Because ⁠Wegovy® slows how quickly food leaves your stomach, meals that used to feel fine may suddenly feel like too much.
• How long will it last? There’s no set timeline. Research hasn’t established a typical duration for indigestion with Wegovy®. It may come and go depending on your dose, portion sizes, and what you eat.
• What might help: ⁠GLP-1 guidance recommends smaller portions, eating slowly, and avoiding lying down right after eating. Pay attention to foods that make your symptoms worse.

Noom’s ⁠guide to what to eat on Wegovy® has more tips for eating comfortably while taking the medication.

9. Dizziness (8%)

Dizziness was ⁠reported by about 8% of adults taking Wegovy® in clinical trials. There are several possible reasons it might happen. Dehydration can contribute, particularly if you’ve had vomiting or diarrhea, and dizziness can also be a sign of low blood sugar in people with diabetes.

• What you might experience: You may feel lightheaded, unsteady, or dizzy, particularly when you stand up.
• How long will it last? There’s no set timeline. Research hasn’t established how long dizziness with Wegovy® typically lasts. Brief lightheadedness may improve once you address things like dehydration, but repeated or persistent dizziness deserves a conversation with your healthcare provider.
• What might help: Stay hydrated, make sure you’re eating enough, and stand up slowly if you feel lightheaded. These are general strategies rather than treatments specifically studied for Wegovy®-related dizziness. If you have diabetes, dizziness can also be a sign that you should check your blood sugar.

10. Bloating (7%)

Bloating—called abdominal distension in the ⁠Wegovy® prescribing information—affected about 7% of adults taking the injection in clinical trials.

• What you might experience: Your stomach may feel unusually full, tight, or swollen after eating. Bloating may be more noticeable after a large meal or when you’re also dealing with constipation.
• How long will it last? There’s no set timeline. Research hasn’t established how long Wegovy®-related bloating typically lasts. It may come and go as your body adjusts or depending on what and how much you eat.
• What might help: Smaller meals, slower eating, and limiting carbonated drinks may help if they make you feel overly full or bloated. Gentle movement, such as walking, may also help with digestion. If constipation is contributing, addressing it may help with the bloating too.

What about side effects with Wegovy® HD (7.2 mg)?

Wegovy® HD has many of the same side effects as the standard 2.4 mg injection, but digestive side effects can be more common at the higher dose. One side effect also stands out: dysesthesia, which can feel like tingling, burning, numbness, or unusually sensitive skin. In ⁠research comparing the two doses, about 23% of people taking 7.2 mg reported dysesthesia compared with 6% taking 2.4 mg.

• Are the side effects different from the 2.4 mg injection? Mostly no. Both doses commonly cause digestive symptoms like nausea, diarrhea, vomiting, and constipation. Overall, about 71% of people taking 7.2 mg experienced a digestive side effect compared with 61% taking 2.4 mg.
• What’s the most common side effect? Digestive side effects are still the most common overall. The biggest difference to know about with Wegovy® HD is the higher rate of dysesthesia.

Learn more about ⁠Wegovy HD 7.2 mg and how it compares with 2.4 mg and read our ⁠complete guide to dysesthesia.

What about side effects with the Wegovy® pill?

The Wegovy® pill contains the same active ingredient as the injection—semaglutide—so its side effects look pretty similar. Digestive problems are the most common, including nausea, diarrhea, vomiting, and constipation. In ⁠research on the 25 mg Wegovy® pill, about 74% of people experienced a digestive side effect.

• Are the side effects different from the injection? Not dramatically. Both forms have similar types of digestive side effects, but we don’t have a head-to-head study showing that one causes fewer side effects overall. One obvious difference is that the pill doesn’t cause injection-site reactions.
• What’s the most common side effect? Digestive side effects lead the list, just as they do with the injection. Nausea is among the most common individual side effects.

For more detail, see Noom’s ⁠complete guide to Wegovy® pill side effects or our ⁠Wegovy® pill vs. injection comparison.

FAQs about Wegovy® side effects

Do Wegovy® side effects go away?

Many do. ⁠Research involving more than 2,000 people taking semaglutide 2.4 mg found that nausea, diarrhea, and vomiting were usually temporary and became less common over time. Constipation can stick around longer, with episodes typically lasting about 47 days compared with eight days for nausea, three days for diarrhea, and two days for vomiting.

Does the Wegovy® pill have fewer side effects than the injection?

Not necessarily. The pill and injection contain the same active ingredient, semaglutide, and both commonly cause nausea, diarrhea, vomiting, constipation, and other digestive symptoms. There hasn’t been a head-to-head study designed to determine which form causes fewer side effects overall, so percentages from separate studies shouldn’t be directly compared. See Noom’s ⁠Wegovy® pill vs. injection comparison for a closer look at the differences.

Are Zepbound’s side effects different from Wegovy®’s?

They’re similar. Both Zepbound and Wegovy® most commonly cause digestive side effects such as nausea, diarrhea, constipation, and vomiting. In ⁠research directly comparing the two medications, digestive side effects were common with both and were generally mild to moderate, particularly while doses were being increased. Noom’s ⁠Wegovy® vs. Zepbound side-effects comparison breaks down the differences.

What are the long-term side effects of Wegovy®?

The most common digestive side effects tend to become less frequent as treatment continues, but Wegovy® also has less common serious risks, including pancreatitis, gallbladder problems, severe digestive problems, and kidney injury related to dehydration. The ⁠Wegovy® prescribing information also carries a boxed warning about thyroid C-cell tumors seen in rodents; it isn’t known whether Wegovy® causes these tumors in humans.

What should I avoid eating on Wegovy®?

There aren’t any foods that everyone taking Wegovy® needs to avoid, but greasy, fried, rich, or very sweet foods may make digestive symptoms worse for some people. Smaller portions and lower-fat foods may be easier to tolerate when you’re feeling nauseated or overly full. Noom’s ⁠guide to what to eat on Wegovy® has more ideas for managing side effects while still getting the nutrition you need.

The bottom line: Side effects with Wegovy® are common, but often temporary and manageable

If you’re considering the Wegovy® injection, side effects are part of the picture—but they won’t look the same for everyone. Nausea is the most common, affecting about 44% of people in clinical trials, followed by diarrhea, vomiting, and constipation. Most digestive side effects are mild to moderate and tend to be most noticeable while your dose is increasing, then become less frequent as treatment continues.

Knowing what to expect can make those first few months easier. Eating smaller meals, staying hydrated, and paying attention to which foods make symptoms better or worse can help. And if a dose increase is particularly difficult, talk to your prescriber rather than trying to push through it. Your dosing schedule may be able to be adjusted while your body catches up.

It’s also important to know the difference between an uncomfortable but expected side effect and something that needs medical attention. Severe or persistent abdominal pain, repeated vomiting, signs of dehydration, or other symptoms that feel significantly different from typical stomach upset are reasons to contact your healthcare provider.

Ultimately, how well Wegovy® works for you includes more than the number on the scale. How you feel and how well you tolerate the medication matter, too. If side effects are getting in the way, your clinician can help you decide whether you need more time, a slower dose increase, or a different approach.

If you’re considering Wegovy® or another weight-loss medication, see if you qualify for Noom Med. If eligible, you’ll be connected with a licensed clinician who can help you compare your options and prescribe medication when appropriate, while Noom’s behavior-change support helps you build habits that can support long-term progress.