14 Ozempic side effects you should be aware of 

Ozempic (semaglutide) is a FDA-approved injectable drug that helps people with type 2 diabetes mellitus control their blood sugar levels, and reduces the risk of heart attack and stroke in people with type 2 diabetes and heart disease. In combination with lifestyle changes like diet and exercise, Ozempic may also be prescribed off-label for weight management in people with obesity and overweight. 

Gastrointestinal side effects from Ozempic are common, but manageable. They include nausea, vomiting, diarrhea, abdominal pain, and constipation. Serious side effects are rare, and may include pancreatitis (inflammation of the pancreas), diabetic retinopathy (vision damage), hypoglycemia (low blood sugar), kidney problems, or an allergic reaction. 

In general, side effects are most common when you start using Ozempic and as you increase your dose. Higher doses of Ozempic can come with a higher risk of side effects. The good news is, Ozempic side effects tend to lessen with time as your body gets used to taking the medication. 

Below, we review the Ozempic side effects you may experience, when to be concerned, and what you can do to find relief.

1. Nausea

Nausea is the most common side effect of Ozempic. In one study, up to 44% of people taking a 2.4 mg dose of semaglutide per week for weight management experienced nausea. Nausea was most common when the participants began using Ozempic. 

As with other side effects associated with Ozempic, people taking a higher dose of Ozempic are more likely to experience nausea. In clinical trials, around 20% of people taking 1 mg of Ozempic experienced nausea, compared with only 16% of people taking 0.5 mg of Ozempic. 

Novo Nordisk, the manufacturer of Ozempic, recommends the following to manage nausea when taking Ozempic:

• Avoid fried, greasy, or sugary foods

• Eat bland foods, like crackers or rice

• Eat water-rich foods, like soup

• Eat slowly

• Drink ice-cold water

• Go outside for some fresh air 

• Avoid lying down after you eat

You can also try eating smaller portions, and paying attention to how you feel when you eat. Whenever you start to feel full, stop eating. 

Health experts also recommend drinking lots of fluids, especially water, and incorporating more fruits, vegetables, and grains into your diet. Conveniently, these dietary recommendations are all considered part of a diabetes-friendly diet.

2. Vomiting

Vomiting is another common side effect when taking Ozempic. It is less common than nausea, but between 5% to 9% of people may experience vomiting when taking Ozempic for type 2 diabetes, depending on the dose they take. 

As with nausea, vomiting is more common when you first start taking Ozempic, and when increasing your dose. Vomiting is also more common when taking higher doses of semaglutide for weight loss. Vomiting can lead to dehydration. If you experience vomiting while taking Ozempic, be sure to rehydrate by drinking plenty of water. 

If you notice severe abdominal pain, which may or may not be accompanied by vomiting, and if that pain radiates to your back, contact your health provider immediately. This can be a sign of pancreatitis, a serious inflammation of the pancreas.

3. Diarrhea

Diarrhea is another common side effect of Ozempic, affecting around 8% to 9% of people taking Ozempic for type 2 diabetes, and 31% of people taking a higher 2.4 mg dose of semaglutide for weight management. Like nausea and vomiting, it is most common when increasing your dose of Ozempic and goes away as your body gets used to it.

If you experience diarrhea while taking Ozempic, stay hydrated by drinking plenty of fluids, as diarrhea can lead to dehydration. 

4. Abdominal pain

Some people experience mild to moderate stomach pain, discomfort, or swelling when taking Ozempic. This side effect affects fewer than one in ten people taking Ozempic. For relief, try taking a warm bath or using a heating pad.

If you experience severe stomach pain, it may be a sign of something more serious, like pancreatitis — especially if the pain does not go away. The pain may radiate to your back, and may or may not be accompanied by vomiting. To be safe, contact your health provider immediately if you experience this and follow their medical advice.

5. Constipation

Up to 5% of people will experience constipation as a side effect of Ozempic. While constipation is a less common side effect, it can last longer than the other gastrointestinal side effects. In one trial, people taking a high dose of semaglutide for weight loss experienced constipation for nearly a month, compared with only a few days of nausea, vomiting, or diarrhea. 

Fortunately, many of the recommendations for relieving constipation also tend to help with blood sugar control and weight management, the two conditions Ozempic can help with. For example, regular exercise not only relieves constipation, but can be particularly beneficial to those managing type 2 diabetes or their body weight. 

6. Gas, burping, and acid reflux

Some people taking Ozempic experience additional gastrointestinal side effects, such as mild burping, flatulence, and acid reflux. Flatulence is more common with higher doses of Ozempic, while burping and acid reflux may be more common with lower 0.5 mg doses of Ozempic.

Some of these side effects can be mitigated by eating more slowly. Burping and flatulence can occur when you swallow too much air, which can happen when you eat too quickly. Slowing down while you eat can minimize these side effects, while also relieving the potential nausea that can occur with Ozempic. 

Drinking lots of water and limiting carbonated beverages can also help. Many of the foods you should avoid while taking Ozempic can contribute to acid reflux — such as high-fat foods, carbonated beverages, and spicy, salty, or fried foods. Limiting your intake of these foods can be beneficial for managing your diabetes and reducing your chances of experiencing heartburn.

While it’s important for people with type 2 diabetes to eat foods with the daily recommended minimum of fiber, too much fiber can cause flatulence. If you notice persistent flatulence, talk to your health care provider or a nutritionist about how you can adjust your diet to get enough fiber without having to take supplements.

7. Pancreatitis

Pancreatitis describes a serious inflammation of the pancreas. It is a rare, but serious, side effect of Ozempic. If you experience severe, persistent stomach pain, stop using Ozempic and call your healthcare provider immediately. The pain may radiate to your back, and you may or may not experience vomiting as well. 

If your healthcare provider confirms you have pancreatitis, they will treat the pain and might recommend an alternative diabetes medication or weight loss drug for you to take instead of Ozempic. 

8. Diabetic retinopathy complications

Diabetic retinopathy describes vision damage or changes that may develop as a complication of type 2 diabetes. In clinical trials, those taking Ozempic were more likely to experience complications of diabetic retinopathy especially when they had a history of diabetic retinopathy. 

While researchers don’t know why, diabetic retinopathy can temporarily worsen when someone experiences sudden improvement in their blood glucose levels — as can occur when taking Ozempic. Signs of diabetic retinopathy include:

• Blurred vision

• Seeing floaters

• Partial or total vision loss

If you notice vision changes while taking Ozempic, tell your healthcare provider. Also, be sure to tell your healthcare provider if you have diabetic retinopathy before you start using Ozempic.

9. Hypoglycemia

While it is rare, people who take medications that lower blood sugar, such as insulin or sulfonylureas, are at an increased risk of experiencing hypoglycemia (low blood sugar) when taking Ozempic. If you also take insulin or sulfonylureas, your health provider may lower the dose of these drugs to reduce your risk of hypoglycemia.

If you notice signs of low blood sugar, contact your health provider. These signs may include:

• Dizziness

• Sweating

• Confusion

• Drowsiness

• Headache

• Blurred vision

• Slurred speech

• Shakiness

• Rapid heartbeat

• Hunger

• Weakness

• Feeling jittery

• Anxiety, irritability, or other mood changes

10. Kidney problems

Taking glucagon-like peptide-1 (GLP-1) receptor agonists, like Ozempic, may worsen renal failure or damage in people with kidney problems. Kidney injury can also occur in people who do not have underlying chronic kidney disease while taking Ozempic. The most noticeable sign of acute kidney injury is a decline in urine output. You may also notice fatigue or swelling.

Kidney injury is more common in people who experience nausea, vomiting, diarrhea, and dehydration that can occur due to these side effects. If you experience these side effects while taking Ozempic, be sure to drink lots of fluids to rehydrate yourself.

If you have had kidney issues in the past, tell your healthcare provider before starting Ozempic so they can take extra care when escalating your dose. 

11. Allergic reaction

Fewer than 1% of people will experience a rare injection site reaction — rash or itching — around where they inject Ozempic. However, some people may be allergic to semaglutide or the other ingredients in Ozempic, which can cause a serious allergic reaction. 

Semaglutide is the main active ingredient in Ozempic. Other inactive ingredients include disodium phosphate dihydrate, propylene glycol, phenol and water. 

If you notice any of the following, stop using Ozempic and seek medical attention immediately:

• Itching

• Rash

• Difficulty breathing

12. Gallbladder problems

Gallbladder issues, especially cholelithiasis (gallstones), are a rare, but possible side effect when taking Ozempic or other GLP-1 receptor agonists like Wegovy. Gallbladder problems affect fewer than 3% of people taking Ozempic for weight loss or type 2 diabetes. Signs of gallbladder issues include sharp, persistent abdominal pain, which may be accompanied by nausea, vomiting, or sweating. 

Sometimes gallstones are asymptomatic and don’t require treatment, while more serious complications can require surgery to remove the gallbladder. A low-fat diet, exercise, and weight loss can help prevent gallstones. Tell your healthcare provider if you have a history of gallbladder disease before starting Ozempic.

13. Other Ozempic side effects

Fewer than 1% of people experience other side effects while using Ozempic, such as fatigue, dizziness, or dysgeusia. Dysgeusia is a taste disorder where foods taste differently than they should, such as tasting bitter or metallic.

Dizziness can be a sign of low blood sugar or hypoglycemia, which can be more common for people who take Ozempic with insulin or sulfonylurea. If you notice other symptoms of hypoglycemia, such as sweating or blurred vision, contact your health provider.

14. Thyroid tumors

Finally, studies in rodents have found a link between medullary thyroid carcinoma, a type of thyroid cancer, and Ozempic. While it is not known if the same risk exists in humans, the FDA has issued a black box warning for Ozempic, which is the highest warning it issues. Given this risk, Ozempic should not be taken by people with a personal or family history of medical conditions that increase their risk for thyroid cancer, such as medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2 (MEN 2). 

Other people who should avoid using Ozempic include those with a history of pancreatitis, diabetic retinopathy, hypoglycemia, acute kidney injury, or acute gallbladder disease, as well as anyone who is pregnant or breastfeeding. Women who are planning to get pregnant should stop using Ozempic at least two months before getting pregnant, if possible. 

While serious side effects may occur with Ozempic, they are rare. For most people taking Ozempic, side effects are mild to moderate and lessen with time. If you experience severe side effects, or it doesn’t seem like your side effects are going away, contact your health provider.

Felix Gussone, MD

Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.