Ozempic’s Side Effects: What to Know

Medically Reviewed By Amber R. Watson, PharmD
Ozempic has a boxed warning for the risk of thyroid tumors. This is a serious warning from the Food and Drug Administration (FDA). For details, see the “ Ozempic: Side effects explained” section below.

Ozempic: Introduction

Ozempic is a brand-name prescription drug. It’s a type of drug called a glucagon-like peptide 1 (GLP-1) receptor agonist, and it contains the active drug semaglutide. It comes as a solution in prefilled pens and is given by subcutaneous injection.

Ozempic is typically used long term. It is approved by the Food and Drug Administration (FDA) to:

Similar to other drugs, Ozempic may cause side effects. Read below for information about possible side effects, including common, mild, and serious ones.


For a general overview of Ozempic, including details about its uses, see this article.

If you’d like to take Ozempic, search here to find a healthcare professional who might prescribe it.

Ozempic: More common side effects

Some of Ozempic’s side effects may be more common than others. These side effects may last only a few days to weeks. However, some side effects may last longer or become severe or bothersome. Tell your doctor or pharmacist if you have concerns about any side effects with Ozempic.

In Ozempic’s clinical studies, these were some side effects that occurred more often:

  • abdominal pain*
  • nausea and vomiting*
  • constipation*
  • diarrhea

* For more information about this side effect, see “Ozempic: Side effects explained” below.

Ozempic: Mild side effects

Ozempic can cause mild side effects, which are listed below. However, this list doesn’t include all possible mild side effects. To learn more about Ozempic’s side effects, view the drug’s prescribing information.

Ozempic’s mild side effects include:

The side effects listed above may last only a few days to weeks. However, some side effects may last longer or become severe or bothersome. Tell your doctor or pharmacist if you have concerns about side effects with Ozempic.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you develop a side effect while taking Ozempic and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Ozempic: Side effects explained” below.

Ozempic: Serious side effects

It’s possible to have serious side effects with Ozempic. Serious side effects are listed below, but this list may not include all possibilities.

In clinical studies, serious side effects were not the most common side effects reported, but they did happen. Certain factors may increase your risk for serious side effects. To learn more about Ozempic’s side effects, view the drug’s prescribing information.

Call your doctor right away if you have serious side effects with Ozempic. However, if you think you’re having a medical emergency or have life threatening side effects, call 911 or your local emergency number.

Serious side effects of Ozempic and their possible symptoms include:

  • Hypoglycemia (low blood sugar). Symptoms can include:
    • blurred vision
    • dizziness
    • weakness
    • sweating
    • fast heartbeat
    • confusion
    • drowsiness
    • irritability or jitteriness
    • headache
  • Pancreatitis (inflammation in the pancreas). Symptoms can include:
    • abdominal and back pain
    • nausea
    • vomiting
    • fever
    • bloated or swollen abdomen
    • fast heartbeat
  • Kidney problems. Symptoms can include:
    • pain in your sides, back, or abdomen
    • swelling in your ankles or legs
    • fatigue
    • nausea
    • urinating a smaller amount than usual
  • Gallstones (hardened deposits in your gallbladder). Symptoms can include:
    • abdominal pain, usually in the upper right area of your abdomen
    • fever
    • chills
    • sweating
    • appetite loss
    • nausea
    • vomiting
  • Diabetic retinopathy.*
  • Risk of thyroid tumors.†
  • Allergic reaction.‡

* For more information about this side effect, see “Ozempic: Side effects explained” below.
Ozempic has a boxed warning for this side effect. This is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Ozempic: Side effects explained” section below.
‡ An allergic reaction is possible after taking Ozempic. However, this side effect wasn’t reported in clinical studies. For more information about this side effect, see “Ozempic: Side effects explained” below.

Ozempic: Side effects explained

Here’s detailed information about some of Ozempic’s side effects.

Risk of thyroid tumors

Ozempic has a boxed warning regarding the risk of thyroid tumors. A boxed warning is the strongest warning required by the Food and Drug Administration (FDA). These warnings alert doctors and patients about drug effects that may be dangerous.

Animals given Ozempic had an increased risk of thyroid tumors in clinical studies. There have also been reports of thyroid cancer with the use of other medications in the same drug class as Ozempic. It’s not clear whether Ozempic causes thyroid tumors in humans.

Due to this possible risk, Ozempic should not be used if you have a personal or family history of certain types of thyroid cancer.

Symptoms of thyroid tumors include:

What to do

Talk with your doctor about your risk of developing thyroid tumors.

Before starting Ozempic, tell your doctor if you or your family have a history of medullary thyroid carcinoma (MTC) or a rare genetic (inherited) condition called multiple endocrine neoplasia syndrome type 2 (MEN 2). Having MEN 2 increases your risk of thyroid tumors.

Also, if you have symptoms of a thyroid tumor while taking Ozempic, tell your doctor right away.

Nausea and vomiting

The most common side effect of Ozempic in clinical studies was nausea. Vomiting was also a common side effect. However, vomiting happened less often than nausea.

Both side effects happened more often in people whose dosage of Ozempic was higher or recently increased.

See Ozempic’s prescribing information to learn how often these side effects occurred during clinical studies.

What to do

If you have nausea or vomiting with Ozempic, talk with your doctor. They may advise that you eat a bland diet that doesn’t contain greasy or sugary foods. They may also recommend that you slowly drink liquids such as water, ginger drinks, or peppermint tea to help prevent dehydration and ease nausea.

Your nausea and vomiting may lessen or go away with time. However, if these side effects become bothersome, talk with your doctor.

Constipation

Constipation was a common side effect of Ozempic in clinical studies.

Symptoms of constipation include:

  • bloating or swelling in your abdomen
  • cramping or pain in your abdomen
  • passing hard or lumpy stools
  • straining to have a bowel movement

See Ozempic’s prescribing information to learn how often this side effect occurred in clinical studies.

What to do

If you have constipation with Ozempic, talk with your doctor. They can advise ways to help relieve your symptoms without medication. This can include drinking plenty of water and increasing fiber-containing foods in your diet. They may also advise that you avoid skipping meals and consuming processed foods.

Talk with your doctor if your constipation does not ease while taking Ozempic.

Abdominal pain

Abdominal pain was a commonly reported side effect of Ozempic in clinical studies. This type of pain can be sharp, dull, or intermittent. It can also feel like cramps or aches.

Keep in mind that Ozempic can cause other digestive side effects such as diarrhea, flatulence (gas), and constipation. These other side effects may contribute to stomach pain.

Severe abdominal pain with Ozempic can be a symptom of pancreatitis, a less common but serious side effect of the drug. (With pancreatitis, the pancreas is inflamed.)

Tell your doctor right away if you have stomach pain that spreads to your back. Also let them know if you have this side effect in combination with vomiting. These can be signs of pancreatitis.

See Ozempic’s prescribing information to learn how often this side effect occurred during clinical studies.

What to do

If your symptoms are mild, talk with your doctor. To help ease your abdominal pain, they may recommend that you:

  • use a heating pad
  • take a warm bath
  • drink chamomile or peppermint tea
  • drink plenty of water or clear liquids

However, tell your doctor if your pain doesn’t go away or becomes severe and spreads to your back. Also let your doctor know if you have vomiting. These symptoms could be signs of pancreatitis.

Diabetic retinopathy

Diabetic retinopathy is an eye disease that occurs in people with diabetes. This condition damages the small blood vessels in the eyes.

Symptoms of diabetic retinopathy can include:

  • vision changes
  • vision loss
  • poor night vision

In clinical studies, diabetic retinopathy occurred in some people taking Ozempic. The risk for complications from the condition was increased in people who’d already had diabetic retinopathy in the past.

Possible complications of diabetic retinopathy include eye bleeding and glaucoma. (With glaucoma, fluid builds up in the eye and leads to problems such as vision loss.)

The effect of long-term use of Ozempic on diabetic retinopathy complications is unknown.  

See Ozempic’s prescribing information to learn how often this side effect occurred during clinical studies.

What to do

Tell your doctor right away if you develop symptoms of diabetic retinopathy. Also, if you have a history of diabetic retinopathy, tell your doctor. They may monitor you more closely than usual during treatment with this drug.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Ozempic. A more severe allergic reaction is rare but possible.

Allergic reaction wasn’t reported in clinical studies of Ozempic. However, this side effect has been reported since the drug became available for use.

Possible symptoms of mild and serious allergic reactions are listed in the table below.

Mild allergic reaction symptoms Serious allergic reaction symptoms
• itching trouble breathing
rash • swelling in your throat or mouth
flushing • swelling under your skin, possibly in your hands, feet, lips, or eyelids

If you have an allergic reaction to Ozempic, call your doctor right away. This is important to do because the reaction could become severe.

However, if you’re having a medical emergency or your symptoms feel life threatening, call 911 or a local emergency number.

Ozempic: Weight loss

As Ozempic can decrease appetite, weight loss may occur with use of the drug. However, weight loss is not an approved use of Ozempic.

Another medication with the same active drug is approved for use in certain adults to help manage weight. This medication, called Wegovy, is prescribed in combination with diet and exercise for long-term weight management. Both Ozempic and Wegovy contain the active drug semaglutide.

If you’re concerned about changes in your weight with Ozempic, talk with your doctor. If you’d like to learn about medications used for weight management, let your doctor know.

Ozempic: Common questions about side effects

Here are some common questions about the drug’s side effects and answers to them. Talk with your doctor if you have other questions about this drug.

Is headache a side effect of Ozempic?

No, Ozempic isn’t likely to cause headaches. Headache wasn’t reported as a side effect in clinical studies of Ozempic.

However, headache is a symptom of hypoglycemia (low blood sugar). And hypoglycemia is a side effect of Ozempic.

If you experience headaches with Ozempic, talk with your doctor. They can help determine the cause of this symptom and advise on ways to relieve your headaches. They can also recommend ways to prevent hypoglycemia.

Other drugs for type 2 diabetes can increase your risk of hypoglycemia. Examples include insulin or medications that cause your body to produce more insulin, such as insulin secretagogues. You may have a headache from low blood sugar if you’re taking these other diabetes drugs with Ozempic.

For more information about symptoms of hypoglycemia, see “Ozempic: Serious side effects” above.

Does Ozempic cause hair loss?

No, hair loss was not reported as a side effect of Ozempic in clinical studies. However, there have been cases of hair loss in people with type 1 and type 2 diabetes. Keep in mind that Ozempic is used to treat type 2 diabetes.

If you experience hair loss with Ozempic, it may be due to your condition, not the medication itself.

Talk with your doctor if you have concerns about hair loss.

Can I have injection-related side effects from using Ozempic pens?

Yes, injection-related side effects were reported in clinical studies of Ozempic. These symptoms included redness and discomfort at the site where Ozempic was injected. However, these side effects were not common.

Injection-related side effects should not last long. If the discomfort or discoloration does not go away or worsens, talk with your doctor.

Ozempic comes as a solution in prefilled pens. It’s administered as a subcutaneous injection in the thigh, abdomen, or upper arm. If you’re injecting Ozempic in the same area of the body, inject the doses into different sites to help prevent skin problems.

If you experience bothersome injection-related side effects with Ozempic, talk with your doctor.

Ozempic: Precautions

Ozempic comes with several precautions.

Boxed warning: Risk of thyroid tumors

Ozempic has a boxed warning for the risk of thyroid tumors. This is a serious warning from the Food and Drug Administration (FDA). For details, see the “Ozempic: Side effects explained” section above.

Other precautions

Be sure to talk with your doctor about your health history before taking Ozempic. This drug may not be the right treatment option if you have certain medical conditions or other factors that affect your health.

The conditions and factors to consider include those described below.

Kidney problems. Medications in the same drug class as Ozempic have caused sudden, severe kidney injury and worsening chronic kidney failure. Many of these cases occurred in people who also had nausea, vomiting, diarrhea, or dehydration. Tell your doctor if you experience these symptoms with Ozempic. They may be signs of a kidney problem. Also let your doctor know if you have or have had kidney problems in the past. They may monitor you more closely than usual or prescribe a different treatment for your condition.

Pancreatitis. Pancreatitis (inflammation of the pancreas) can occur with Ozempic. Talk with your doctor if you’ve had pancreatitis. They may recommend a different treatment option for you. If you think you have pancreatitis, stop taking Ozempic and call your doctor right away. If your doctor determines that you have pancreatitis, they will have you stop Ozempic and they’ll recommend another treatment.

Taking certain other diabetes drugs. There’s an increased risk of hypoglycemia (low blood sugar) if Ozempic is taken with certain other diabetes medications. Tell your doctor about any other diabetes drugs you may take. They may lower the dose of your other diabetes medications to help reduce your risk of hypoglycemia with Ozempic. For more details on hypoglycemia, see the “Ozempic: Serious side effects” section above.

Allergic reaction. If you’ve had an allergic reaction to Ozempic or any of its ingredients, your doctor will likely not prescribe Ozempic. Ask your doctor which other medications may be better options for you.

Diabetic retinopathy. Tell your doctor if you have diabetic retinopathy (a diabetes-related eye condition). Ozempic may worsen it. If you have diabetic retinopathy, your doctor may monitor you more closely than usual while you are taking Ozempic. Tell your doctor if you have any vision changes during your Ozempic treatment.

Consuming alcohol during Ozempic treatment

It’s not known whether it’s safe to drink alcohol while taking Ozempic. Ozempic lowers blood sugar, as does alcohol. For this reason, there is an increased risk of hypoglycemia (low blood sugar) if Ozempic and alcohol are used together.

In addition, long-term alcohol use can cause pancreatitis (swelling of the pancreas). Pancreatitis is also a serious side effect of Ozempic.

If you drink alcohol, talk with your doctor about a safe amount to drink while taking Ozempic.

Pregnancy and breastfeeding during Ozempic treatment

Read below for information on taking Ozempic while pregnant or breastfeeding.

Pregnancy. It’s unknown whether it is safe to use Ozempic during pregnancy or while breastfeeding. Your doctor will likely recommend you do not take Ozempic while you’re pregnant.

The drug’s manufacturer recommends stopping Ozempic 2 months before you plan to become pregnant. However, don’t stop taking your medication or change your dose without first talking with your doctor.

If you plan to become pregnant, talk with your doctor about treatment options to manage your blood sugar while pregnant. If you become pregnant while taking Ozempic, tell your doctor right away.

Breastfeeding. It’s unknown whether Ozempic can pass into breast milk. Your doctor will likely recommend you do not take Ozempic while you’re breastfeeding. Talk with your doctor about how to safely feed your child while being treated with Ozempic.

Ozempic: What to discuss with your doctor

Talk with your doctor or pharmacist to find out more about Ozempic. If you have questions about the drug’s side effects, your pharmacist or healthcare professional can help answer them for you.

In addition to discussing Ozempic with your doctor, you may find the following articles helpful.

  • Overview of Ozempic. To read an overview of Ozempic, see this article.
  • Drug comparison. To learn how Ozempic compares with Trulicity, read this article. And to learn how Ozempic compares with Victoza, read this article.
  • Details about type 2 diabetes. To learn more about type 2 diabetes, which Ozempic is used to treat, see this article.

Disclaimer: Healthgrades has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.

Medical Reviewer: Amber R. Watson, PharmD
Last Review Date: 2022 Apr 24
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.