What are 4 key Ozempic side effects to watch out for?

Key Points

• Ozempic (semaglutide) is medicine used to treat elevated glucose (blood sugar) levels in people with type 2 diabetes, in addition to a healthy diet and an exercise program. It can also help you lose weight, but is not approved by the FDA for this use.
• The most common side effects with Ozempic include stomach problems like nausea, vomiting, diarrhea, stomach pain and constipation. These tend to be mild-to-moderate and usually clear up in a few weeks in most people.
• Low blood sugar (hypoglycemia) is also a common side effect (when used with certain other diabetes treatments) and it may be serious in some people.

You should learn how to recognize signs of hypoglycemia. Other side effects to be aware of include those in the pancreas, gallbladder, kidney, eye, rare thyroid problems like cancer and serious allergic reactions.

What is Ozempic?

Ozempic (semaglutide) is a prescription medicine that belongs to a class of drugs called glucagon-like peptide 1 (GLP-1) receptor agonists. It’s in the same class of drugs and same active ingredient as the medication in Rybelsus (an oral tablet) used for type 2 diabetes and Wegovy (an injection) used for weight loss.

• Ozempic is an injected treatment given once-a-week to adults to help control blood sugar in type 2 diabetes. It’s also used with a healthy diet and regular exercise program.
• It's also used in people with type 2 diabetes and heart (cardiovascular) disease to reduce the risk of a major event like a heart attack, stroke, or death from cardiovascular causes.
• It works by stimulating the secretion of insulin after a meal or snack (glucose), which helps to regulate blood sugar. This process may not work as well as it should in people with type 2 diabetes, so they may benefit from the use of Ozempic.

Ozempic has been shown in studies to lead to significant weight loss, but it’s not specifically approved by the FDA for this use. If weight loss is your only goal and you do not have type 2 diabetes, the brand of semaglutide known as Wegovy is approved for weight loss, but not treatment of type 2 diabetes.

Learn more: Ozempic vs. Wegovy: How do they compare?

Ozempic treatment is recommended for long-term use if it’s effective for you. Because you will use it for a long period of time, it’s important to be familiar with possible side effects and how to recognize and manage them.

Below, we offer tips on how to recognize and manage certain side effects so you can stay on treatment and meet your goals for managing type 2 diabetes. This is not a complete list of all side effects with Ozempic.

4 side effects of Ozempic and how to manage them

Here, let’s look at 4 important side effects with Ozempic. Some side effects are more common than others. Luckily, the most common side effects are usually short-term and only last a few days or weeks in most people. We’ll offer tips on how you can recognize and manage these side effects so you can stay on treatment and meet your goals.

Side Effect #1: Stomach

Stomach (abdominal) side effects with GLP-1 agonist agents like Ozempic are common but tend to be mild and clear up in a few weeks in most people. Stomach side effects can be more common with higher doses.

The most common side effect with Ozempic is nausea and occurs in about 15% to 20% of people.

• Others include vomiting (5% to 9%), diarrhea (8%), stomach-area pain (6% to 7%), and constipation (3% to 7%).
• These side effects occurred at rates higher than the placebo-treated groups (receiving an inactive treatment).
• In general, patients may report higher rates of gastrointestinal side effects.

More patients receiving Ozempic 0.5 mg (3.1%) and 1 mg (3.8%) discontinued treatment due to stomach side effects than patients receiving placebo (0.4%).

The good news is that for most people these side effects are mild, temporary and will not interfere with long-term treatment. They typically subside with a few weeks of starting treatment.

Stomach side effects usually occur at the beginning of treatment and when your dose is increased too quickly. Because of this, your healthcare provider will slowly increase your dose every 4 weeks as needed, until you reach your target dose. You can take Ozempic with or without meals.

Tips for managing stomach side effects

Consider following these tips to help you manage stomach side effects when you start Ozempic:

• eat more slowly
• consume smaller meals
• select more bland, low-fat foods (like crackers, toast and rice)
• avoid greasy, fried foods or sugar treats
• eat foods that contain water (like soup or gelatin)
• don’t lie down right after eating
• drink clear or ice-cold liquids
• if possible, go outside for fresh air if you feel sick to your stomach

Does Ozempic cause an ileus?

In September 2023, the FDA updated a side effect called ileus (an intestinal obstruction) in the product label for Ozempic and other similar medicines (Wegovy, Rybelsus, and Mounjaro).

These side effects were voluntarily reported after Ozempic was approved, so the FDA cannot reliably determine how often this side effect occurs or if the drug actually caused the side effect.

An ileus is an intestinal blockage that results in the failure of the intestinal contents to pass through the gut, but it doesn't involve a physical blockage. An ileus can lead to problems with the muscle or nerves found in the intestine interfere with normal muscle contractions.

Symptoms of an ileus may include:

• stomach area (abdominal) swelling (distention)
• fullness, gas in the stomach area
• stomach area (abdominal) pain and cramping
• breath odor
• constipation
• diarrhea
• inability to pass gas
• vomiting

Related: What is an ileus?

If you experience stomach side effects with Ozempic that bother you, worsen or do not go away, call your healthcare provider right away for further evaluation.

Side Effect #2: Vision changes (diabetic retinopathy)

Diabetic retinopathy is a serious eye disease that can lead to blindness. People with type 2 diabetes and long-term, uncontrolled blood sugar levels are at higher risk.

In this form of retinopathy, blood vessels weaken and leak blood into the surrounding tissues which lead to inflammation. Over time this results in new blood vessels forming that obstruct the retina and can lead to blindness.

Risk factors for developing diabetic retinopathy include: having diabetes for more than 5 years, poor blood sugar control, high blood pressure, high cholesterol, pregnancy, or kidney disease, smoking, eye surgery or other eye problems, a family history of diabetic retinopathy.

Rapid improvement in blood sugar control, as may occur with Ozempic, has also been associated with a temporary worsening of diabetic retinopathy in some patients.

In an Ozempic clinical study, more patients receiving Ozempic (3%) had diabetic retinopathy complications compared to the group taking a placebo (inactive) treatment (1.8%). The risk was higher in patients with a history of diabetic retinopathy (Ozempic 8.2%, placebo 5.2%) than in those without a known history of this eye disease (0.7%, placebo 0.4%).

The effect of long-term blood sugar control with semaglutide on diabetic retinopathy complications has not been studied.

Tips for managing or identifying vision changes

• Before you start Ozempic treatment, you should tell your healthcare provider if you have a history of diabetic retinopathy.
• If you experience any vision changes while using Ozempic, contact your doctor for further evaluation.
• Maintain regular vision check-ups as recommended by your doctor. Your eye care professional or doctor should monitor you for progression of diabetic retinopathy.

Related Questions

• Mounjaro vs Ozempic: How do they compare?
• How do Ozempic, Mounjaro, Wegovy, Zepbound compare for weight loss?
• How long does it take for Ozempic to work?

Side Effect #3: Thyroid tumors or cancer

Your thyroid is a small gland found in the front of your neck area. It helps to control many functions in your body by making and releasing certain thyroid hormones.

One of the the most serious but rare warnings with Ozempic includes a risk for thyroid tumors or thyroid cancer, which has been seen in animal (rat) studies. It is not known if Ozempic will cause thyroid tumors or thyroid cancer in humans, but it carries a Boxed Warning for this possible side effect, the FDA’s most prominent warning.

• Do not use Ozempic if you or anyone in your family have ever had a type of thyroid cancer called medullary thyroid carcinoma (MTC) or if you have an endocrine system condition called Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).
• Other semaglutide products and all GLP-1 receptor agonists also carry this warning.

Cases of MTC have been seen in patients treated with another GLP-1 receptor agonist known as liraglutide (Saxenda, Victoza) after it was approved by the FDA. However, it is not known if liraglutide caused these tumors because there was not enough data in the reports to draw a final conclusion.

Your doctor will check your thyroid gland (found in your neck area) for nodules. A blood test (serum calcitonin) or a thyroid ultrasound (an imaging test) may be used to monitor for thyroid disease, but this is not commonly done because the tests are not very specific. However, if your doctor suspects thyroid disease, they may order these tests and do further evaluations.

Tips for managing possible or identifying thyroid disease or cancer

If you notice any of the following signs or symptoms, contact your doctor right away:

• a lump or swelling in the neck
• neck pain
• a hoarse voice or voice changes
• trouble swallowing
• trouble breathing
• a cough that won’t go away

Side Effect #4: Low blood sugar (hypoglycemia)

The risk of hypoglycemia with GLP1 receptor agonists like Ozempic is low, but may still occur. You may be at a greater risk for this side effect if you also take other drugs for diabetes, including sulfonylureas (for example: glipizide or glyburide) or insulin. Higher doses of Ozempic may also increase your risk for low blood sugar.

Low blood sugar, if it occurs, can be a serious side effect with Ozempic treatment.

Monotherapy

In 30-week long studies, when Ozempic 0.5 mg or 1 mg dose was used as the only diabetes treatment, low blood sugar with symptoms occurred in 1.6% to 3.8% of patients taking Ozempic and 0% taking a placebo (inactive treatment). No severe hypoglycemia was reported with Ozempic monotherapy.

Use with insulin

When Ozempic is used with insulin, hypoglycemia can occur and a dose reduction of the insulin may be needed.

• When Ozempic 0.5 mg or 1 mg dose was used with insulin (with or without metformin), low blood sugar occurred in 16.7% to 29.8% of patients taking Ozempic and 15.2% taking a placebo.
• Severe or documented symptomatic low blood sugar occurred 8.3% to 10.7% of patients and 5.3% in the placebo group.
• Severe low blood sugar was reported in 1.5% of patients receiving the 1 mg Ozempic dose, and none in the other groups.

Use with sulfonylureas

When Ozempic is used with sulfonylureas such as glipizide, glyburide or glimepiride, hypoglycemia can occur and a dose reduction of the sulfonylurea may be needed.

• Severe hypoglycemia occurred in 0.8% and 1.2% of patients when Ozempic 0.5 mg and 1 mg, respectively, was co-administered with a sulfonylurea.
• Documented symptomatic low blood sugar occurred in 17.3% and 24.4% of patients when Ozempic 0.5 mg and 1 mg, respectively, was co-administered with a sulfonylurea.
• Severe or blood glucose confirmed symptomatic hypoglycemia occurred in 6.5% and 10.4% of patients when Ozempic 0.5 mg and 1 mg, respectively, was co-administered with a sulfonylurea.

Low blood sugar has also been reported in patients taking GLP-1 receptor agonists who do not have type 2 diabetes.

Tips for managing or recognizing low blood sugar

Call your doctor right away if you have any of these signs or symptoms:

• dizziness, feeling lightheaded or jittery
• headache
• feeling tired, drowsiness
• anxiety, irritability or other mood changes
• blurred vision
• weakness or shakiness
• a fast heartbeat
• confusion
• slurred speech
• hunger
• sweating

Ask your doctor what you should do if you develop symptoms of low blood sugar. This may include taking glucose (sugar) tablets, a glucose liquid, or fruit juice. You and your doctor may need to more closely monitor your blood sugar during treatment with Ozempic.

Tell your healthcare provider if you are taking other medicines to treat diabetes, including sulfonylureas or insulin. Ozempic slows down your stomach emptying and can affect medications that need to pass through your stomach quickly. Your doctor may need to change your dose of certain diabetes medicines.

This is not a complete list of side effects or warnings with Ozempic. Other important side effects include disease of the pancreas, gallbladder, kidney and serious allergic reactions. If you have questions or concerns about side effects, contact your doctor right away.

You can review all Ozempic side effects in more detail here. You can also review the manufacturer’s Medication Guide and discuss this information with your healthcare provider.

Bottom Line

• Ozempic (semaglutide) is a prescription medicine used to treat high glucose (blood sugar) levels in people with type 2 diabetes, in addition to a healthy diet and increased activity. It's also approved to reduce the risk of major adverse cardiovascular events such as heart attack, stroke, or death in adults with type 2 diabetes and known heart disease
• Common side effects, like stomach-related nausea, vomiting, or diarrhea can occur but tend to be moderate and temporary, improving after several weeks of treatment.
• Other side effects, like those with the thyroid, pancreas, gallbladder, and kidney, low blood sugar or allergic reactions tend to be less frequent, but can still be severe or even life-threatening. You should learn how to recognize the signs and symptoms of these potential side effects.
• Your doctor may need to adjust your doses of other type 2 diabetes medicine. Tell them if you take a sulfonylurea medicine or insulin. Do not exceed the dose of Ozempic prescribed by your healthcare provider, which may increase your risk for more severe side effects.

This is not all the information you need to know about Ozempic (semaglutide) for safe and effective use and does not take the place of your doctor’s directions. Review the full Ozempic information and discuss this information and any questions you have with your doctor or other health care provider.