Rybelsus (semaglutide) can cause side effects that range from mild to serious. More common side effects include constipation and diarrhea. If side effects from Rybelsus become difficult to tolerate, talk with your doctor about coping tips or other treatment options.

Rybelsus is used with a nutritious diet and exercise to manage blood sugar in adults with type 2 diabetes.

The active ingredient in Rybelsus is semaglutide. (An active ingredient is what makes a drug work.) The drug comes as a tablet that you swallow.

Keep reading to learn about the common, mild, and serious side effects that Rybelsus can cause.

Rybelsus has a boxed warning. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Side effects explained” section later in this article.

With Rybelsus, some side effects are more common than others. The list below includes the most reported side effects:

Nausea, vomiting, and diarrhea are more common when you first start taking Rybelsus or after dose increases. This is because your body needs time to get used to the medication. For most people, these side effects usually go away within a few days or weeks of dosage increases.

For more information about some of these side effects, see the “Side effects explained” section.

Rybelsus can cause mild side effects in some people. Examples of mild side effects that have been reported with Rybelsus include:

To learn more about some of these side effects, see the “Side effects explained” section.

In most cases, these side effects should be temporary. And some may be easily managed, too. But if you have any symptoms that are ongoing or that bother you, talk with your doctor or pharmacist. And do not stop using Rybelsus unless your doctor recommends it.

Rybelsus may cause mild side effects other than the ones listed above. See the Rybelsus prescribing information for details.

Do Rybelsus side effects go away?

Yes, most common and mild side effects of Rybelsus are expected to go away or improve within 4 weeks.

Many people experience mild digestive system problems, such as nausea or diarrhea, when starting Rybelsus or increasing the dose. These digestive side effects tend to improve or go away on their own as your body adjusts to the medication. This process can take up to a few weeks.

In rare cases, it’s also possible for these side effects to continue until you stop Rybelsus treatment.

To help prevent common digestive system side effects, your doctor will likely start you on a low Rybelsus dosage. Then, they’ll increase your dose slowly, no more than once every 30 days.

If you have persistent or bothersome side effects with Rybelsus, talk with your doctor. They can provide more specific details about how long these effects should last. They may also be able to recommend medications or other ways to help manage those side effects.

Serious side effects from Rybelsus aren’t common, but they can happen. Serious side effects that have been reported with Rybelsus include:

If you develop serious side effects while taking Rybelsus, call your doctor right away. If the side effects seem life threatening or if you think you’re having a medical emergency, immediately call 911 or your local emergency number.

For more information about some of these side effects, see the “Side effects explained” section.

Note: After the FDA approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medication safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect while taking Rybelsus and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Allergic reaction

For some people, Rybelsus can cause an allergic reaction.

This side effect wasn’t reported in the drug’s studies, but it’s been reported since Rybelsus was approved for use.

In general, symptoms of an allergic reaction can be mild or serious.

What might help?

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep taking Rybelsus.

If you have symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Rybelsus, they may have you switch to a different treatment.

Long-term side effects are possible with Rybelsus. This includes side effects that may start at any time you’re taking a drug, even if you’ve taken it for a long time. Some side effects of Rybelsus may not go away, even after you stop taking the drug.

Examples of long-term side effects reported with Rybelsus include:

  • pancreatitis
  • kidney problems, such as kidney failure
  • boxed warning: risk of thyroid cancer

To learn more about some of these side effects, see the “Side effects explained” section.

Talk with your doctor to learn more about possible side effects of Rybelsus and how long they may last.

Learn some frequently asked questions and answers about Rybelsus, including information about side effects.

How much does Rybelsus cost? Are savings options available?

The price you’ll pay for Rybelsus can vary. Your cost may depend on your treatment plan, the pharmacy you use, and any insurance coverage you have. To save money on your Rybelsus prescription, explore the coupon options below.

Does the dose of Rybelsus I take, 3 milligrams (mg), 7 mg, or 14 mg, affect my risk of side effects?

It’s possible. In studies, some people chose to stop taking Rybelsus because of digestion-related side effects.* Of these, more people taking a higher strength of Rybelsus (14 mg) stopped treatment compared with those taking a lower strength (7 mg).

All strengths of Rybelsus can cause mild or serious side effects. If you have concerns about side effects with your current dose of the drug, talk with your doctor.

* These included nausea, vomiting, abdominal pain, diarrhea, constipation, and loss of appetite.

Will Rybelsus cause hair loss?

No, Rybelsus shouldn’t cause hair loss. This wasn’t reported as a side effect in studies of the drug.

However, diabetes, the condition that Rybelsus is used to treat, may be linked to hair loss. Other medications or medical conditions can also cause hair loss.

If you’ve experienced hair loss since starting Rybelsus, talk with your doctor. They may want to check for other causes and discuss your treatment options.

Does Rybelsus make you tired?

No, it shouldn’t. In studies of the drug, tiredness wasn’t reported as a side effect.

Rybelsus is known to cause nausea and loss of appetite. And not eating enough nutrient-dense calories can cause fatigue.

To ease nausea, consider trying different foods. Frequently eating snacks instead of three larger meals in a day may help lessen nausea. Choosing nutritious foods over foods with empty calories can give you more energy.

Type 2 diabetes can cause other medical conditions that may result in tiredness, such as heart disease. And some drugs that are used to treat these other conditions can make you feel fatigued, such as blood pressure medications.

If you’re feeling more tired than usual since you started taking Rybelsus, talk with your doctor. They’ll try to find out what’s causing this side effect so it can be treated. And they could change other medications that you might be taking.

How long does Rybelsus stay in your system?

Rybelsus stays in your system for about 5 weeks after your last dose.

If you’re planning a pregnancy, you should wait at least 2 months after stopping Rybelsus before trying to become pregnant. This is because it can take that long before Rybelsus is completely out of your body.

Can you suddenly stop taking Rybelsus?

Yes, you can suddenly stop taking Rybelsus if you and your doctor decide that it isn’t safe or effective for you.

For example, if you develop a serious side effect from Rybelsus, your doctor will have you stop taking it right away. An example is pancreatitis.

If you want to stop taking Rybelsus, talk with your doctor first. It’s important that you have a plan in place to manage your blood sugar before stopping any diabetes treatment.

Learn more about some of the side effects Rybelsus may cause.

Weight loss

Rybelsus is not approved by the FDA for weight loss. It’s approved to improve blood sugar management in adults with type 2 diabetes.

But the way Rybelsus works in your body may cause weight loss. This drug lowers your blood sugar by stimulating a certain hormone. This hormone slows down how fast your stomach empties after eating, which can help you feel full longer. As a result, you’re more likely to consume fewer calories, which can lead to weight loss.

Also, the more common side effects of Rybelsus are related to digestion. These side effects, which include nausea, abdominal pain, and reduced appetite, can cause weight loss. But most of these digestion-related side effects are temporary or can be easily managed.

And remember, this drug is meant to be part of a treatment plan that includes eating a balanced diet and exercising. These healthy practices can also contribute to weight loss.

What might help

For some people with type 2 diabetes, weight loss may be a beneficial side effect of Rybelsus. Losing weight can help improve blood sugar management and prevent diabetes from getting worse. According to a 2020 study, it’s possible that weight loss may even help to reverse type 2 diabetes.

If you’ve recently started taking Rybelsus, it’s common to experience nausea, vomiting, and diarrhea at first. Eating frequent snacks instead of three larger meals in a day may help lessen nausea. Choosing healthy foods can help make sure that your body is still getting some nutrients.

But losing too much weight due to severe vomiting and diarrhea can be harmful. If you’re concerned about weight loss or severe digestion-related side effects from Rybelsus, talk with your doctor. They’ll likely recommend changes to your treatment plan.

Risk of thyroid cancer

Rybelsus has a boxed warning for the risk of thyroid cancer. A boxed warning is the most serious warning from the FDA.

In animal studies, semaglutide (the active drug in Rybelsus) caused thyroid tumors in mice and rats. But animal studies don’t always reflect what will happen in humans.

It’s not known whether Rybelsus causes thyroid cancer in humans. To be safe, you should not take Rybelsus if:

  • you or your family members have had a certain type of thyroid cancer called medullary thyroid carcinoma (MTC)
  • you have a genetic condition called multiple endocrine neoplasia syndrome type 2 (MEN2)

If you take Rybelsus, you should be aware of the possible symptoms of thyroid cancer. These include:

  • a lump or growth in your neck
  • pain in your neck
  • difficulty swallowing
  • difficulty breathing
  • a hoarse voice that doesn’t get better

What might help

Before you start Rybelsus, your doctor will want to know your health history. Tell your doctor if you or someone in your family have or has had MTC or MEN2. They’ll likely recommend a different medication for your type 2 diabetes.

If you develop any possible symptoms of thyroid cancer while taking Rybelsus, tell your doctor right away. They will screen you for this cancer.

If you have questions about your risk for thyroid cancer with Rybelsus, talk with your doctor.

Constipation

Constipation has been reported as a common side effect of Rybelsus.

Everyone experiences some constipation from time to time. But when it’s caused by a medication that you take daily, constipation can become severe. If untreated, constipation can lead to nausea, rectal bleeding, or an intestinal blockage.

Symptoms of constipation may include:

  • having fewer than three bowel movements in a week
  • having stools that are hard to pass
  • passing some stool, but feeling like there’s more that you can’t pass
  • abdominal pain

What might help

Constipation from Rybelsus might not go away on its own. You may need to take certain steps to relieve constipation and prevent it from coming back.

There are several over-the-counter laxatives that you can use to relieve constipation. Some work within days, others within minutes. Depending on how severe your constipation is, you may want quick relief. Here are a few examples:

  • MiraLAX (polyethylene glycol 3350) is a powder that you mix into a liquid and drink. It usually causes a bowel movement within 1 to 3 days.
  • Dulcolax (bisacodyl) rectal suppository usually causes a bowel movement within 15 to 60 minutes.
  • Fleet Saline Enema rectal enema usually causes a bowel movement within 1 to 5 minutes.

Home remedies may help prevent constipation naturally. Increasing your water intake, eating more vegetables, and exercising are a few ways to get your bowels moving regularly.

If you have questions about which option is best for your constipation, talk with your pharmacist or doctor.

Keeping track of side effects

During your Rybelsus treatment, consider keeping notes on any side effects you’re having. Then, you can share this information with your doctor. This is especially helpful to do when you first start taking new drugs or using a combination of treatments.

Your side effect notes can include things like:

  • what dose of drug you were taking when you had the side effect
  • how soon after starting that dose you had the side effect
  • what your symptoms were from the side effect
  • how it affected your daily activities
  • what other medications you were also taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help your doctor learn more about how Rybelsus affects you. And your doctor can use this information to adjust your treatment plan if needed.

Rybelsus comes with several warnings.

Boxed warning: Risk of thyroid cancer

Rybelsus has a boxed warning. A boxed warning is the most serious warning from the FDA. For details, see the “Side effects explained” section.

Other warnings

Rybelsus may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before you take Rybelsus. The list below includes factors to consider.

Delayed digestion: Because of the way Rybelsus works, it may cause gastroparesis (extremely slow digestion). Gastroparesis can also occur as a complication of diabetes. If you already have this disorder, taking Rybelsus could worsen it. In some cases, gastroparesis may lead to serious complications, such as a bowel obstruction. If you already have gastroparesis, your doctor will determine whether Rybelsus is safe for you to take.

Sedation or anesthesia: If you have an upcoming medical procedure that requires sedation or general anesthesia, be sure to tell your care team about all the medications you’re taking. Doctors typically recommend fasting for several hours before surgery to help prevent the risk of aspiration. (With aspiration, food or other substances may rise out of your stomach and enter your airways.)

Because Rybelsus may slow down your digestion, you may need to fast for longer than usual before surgery. Your doctor will advise the safest ways to help reduce the risk of aspiration before your procedure.

Gallbladder problems: Rybelsus may cause sudden gallbladder problems, including gallstones and inflammation. These side effects weren’t reported in studies of Rybelsus, but they’ve been reported since Rybelsus was approved for use.

During treatment, be sure to tell your doctor if you experience any gallbladder-related symptoms. These symptoms include upper abdominal pain, jaundice (yellowing of the skin or eyes), clay-colored stools, or fever. If your doctor confirms that you have a gallbladder problem, they’ll determine whether it’s safe for you to keep taking Rybelsus.

Eye problems related to diabetes: Diabetes can lead to diabetic retinopathy. This is a condition that damages the blood vessels in your retina. In studies, some people with diabetic retinopathy who took Rybelsus developed more severe problems related to this eye condition. If you have diabetic retinopathy, talk with your doctor before starting Rybelsus treatment. They may want to have your eyes checked more often while you’re taking this drug.

Risk of low blood sugar: Although not common, Rybelsus can cause hypoglycemia as a serious side effect. If you’re taking certain diabetes medications, Rybelsus may increase this risk. Examples include insulin and sulfonylureas such as Amaryl (glimepiride). Be sure to tell your doctor about other diabetes medications you take. If your doctor recommends you take Rybelsus with your other diabetes medications, they may have you check your blood sugar levels more often.

Kidney problems: Short-term kidney damage and worsening of long-term kidney disease have been reported with the use of Rybelsus. Symptoms include nausea, vomiting, diarrhea, and dehydration. If you’ve had kidney problems, be sure to tell your doctor before taking Rybelsus. They may check your kidneys with a blood test before you start the drug. They might also recheck your kidneys during treatment, especially if you develop severe vomiting or diarrhea. These side effects can lead to dehydration, which can be harmful if you have kidney problems.

Pancreas problems: In rare cases, pancreatitis has been reported with Rybelsus. If you have a history of pancreas problems, talk with your doctor. They’ll determine whether it’s safe for you to take Rybelsus.

Allergic reaction: If you’ve had an allergic reaction to Rybelsus or any of its ingredients, you should not take Rybelsus. Ask your doctor what other medications are better options for you.

Alcohol and Rybelsus

Rybelsus doesn’t interact with alcohol.

However, you should take Rybelsus on an empty stomach. This means that if you drink, you should not drink alcohol before it’s time for your dose. And you should not consume anything other than 4 ounces (about half a cup) of plain water in the 30 minutes after your dose. This includes other medications.

Pregnancy and breastfeeding while taking Rybelsus

Rybelsus treatment hasn’t been studied in people during pregnancy. So it’s not known whether it can be harmful to take during pregnancy.

Its effects on breastfeeding and breast milk are also unknown.

If you’re pregnant or breastfeeding or planning to become pregnant or breastfeed, talk with your doctor. They’ll help you plan how best to manage your blood sugar levels during this time.

Rybelsus can be an effective treatment for improving blood sugar management in adults with type 2 diabetes. It’s meant to be used together with a nutritious diet and exercise.

As with many other drugs, Rybelsus can cause side effects in some people. You should talk with your doctor to find out whether Rybelsus is safe for you. Some questions that you may want to ask your doctor include:

  • How long do Rybelsus side effects last?
  • Do any of my other medications increase my risk for side effects from this drug?
  • With my current health and medical history, am I at higher risk for serious side effects from Rybelsus?

To learn more about Rybelsus, see these articles:

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Disclaimer: Healthline 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.