Key takeaways

  • Lybalvi (olanzapine/samidorphan) can cause mild or serious side effects. These side effects may be temporary, lasting a few days to weeks.
  • More common mild side effects of Lybalvi include sleepiness, weight gain, and dry mouth. Potential serious side effects include high blood sugar and high cholesterol, requiring monitoring by a doctor.
  • Tardive dyskinesia (involuntary movements) is a rare but serious potential side effect. If it occurs, your doctor may have you switch to a different treatment or prescribe medication to manage the side effect.

Lybalvi is used for schizophrenia and bipolar I disorder treatment in adults. Your doctor might prescribe it along with lithium (Lithobid) or valproate, in some cases.

Like other drugs, Lybalvi can cause mild to serious side effects. Keep reading to learn more about the drug’s side effects and risks. For more information about Lybalvi, including details about its uses, see this in-depth article.

This drug has a boxed warning. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Boxed warning for Lybalvi” section.

Some people may experience mild to serious side effects during Lybalvi treatment. Examples of Lybalvi’s commonly reported side effects include:

Keep in mind that not everyone who takes Lybalvi will have these side effects. And these aren’t the only side effects the drug may cause. The following is more information about other possible mild and serious side effects from Lybalvi.

Like most medications, Lybalvi can cause mild side effects. Examples that have been reported with this drug include:

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

Lybalvi may cause mild side effects other than those listed. See the drug’s prescribing information for details.

For more information about some of these side effects, see “Tips for managing side effects.”

Serious side effects are possible with Lybalvi, although they’re not common.

Serious side effects that have been reported with this drug include:

If you develop serious side effects while taking Lybalvi, call your doctor right away. If the side effects seem life threatening or 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 “Tips for managing side effects” and “Boxed warning for Lybalvi” sections.

Note: After the FDA approves a drug, it tracks 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 Lybalvi and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Allergic reaction

For some people, Lybalvi can cause an allergic reaction. It’s not clear whether allergic reactions happened in Lybalvi’s studies, but they have been reported since the drug 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 continue Lybalvi treatment.

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 Lybalvi, they may have you switch to a different treatment.

Lybalvi has a boxed warning about an increased risk of death when used in older adults (ages 65 years and over) with dementia-related psychosis. Boxed warnings are the most serious warnings from the FDA. It alerts doctors and patients about drug effects that may be dangerous.

Older adults with dementia-related psychosis weren’t included in Lybalvi’s studies. But this increased risk applies to all antipsychotic drugs (including Lybalvi), based on a large review of studies.

What you can do

Due to the increased risk of death, doctors will not prescribe Lybalvi for adults ages 65 years and older with dementia that’s related to psychosis. Doctors will consider other treatments instead.

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

Weight gain

Like all antipsychotic drugs, treatment with Lybalvi may result in weight gain as a side effect.

In one of the drug’s studies, 4 weeks of Lybalvi treatment led to an average weight gain of about 3 kilograms (kg), which is about 6.6 pounds (lb), per person. In this same study, people who took a placebo (a pill with no active drug) gained less than 0.2 kg (about 0.4 lb) on average. (For reference, 1 kg equals about 2.2 lb.)

What you can do

Your doctor will monitor your weight while you’re taking Lybalvi and may want you to monitor it at home, too.

If you have concerns about your weight while taking Lybalvi, talk with your doctor. They can make meal and exercise recommendations and suggest ways to maintain a moderate weight.

Your doctor may prescribe the drug metformin to help manage your weight. Alternatively, they may advise you to stop taking Lybalvi and try a different treatment for your condition.

Tardive dyskinesia

Tardive dyskinesia (TD) is a rare, serious, and possibly irreversible side effect that Lybalvi may cause. It’s a known side effect of antipsychotic drugs, including Lybalvi.

With TD, you develop involuntary movements in parts of your body, most commonly your face or mouth. These movements can include grimacing, thrusting out your tongue, or smacking your lips, among others. You may also have uncontrollable movements in your arms, legs, hands, or other parts of your body.

TD can affect anyone taking an antipsychotic, but older adults who are female are thought to have the highest risk. TD can occur at any time during your Lybalvi treatment. It’s thought your risk may increase the longer you take the drug. If you stop taking Lybalvi, TD may or may not go away.

Note: The use of binary terms such as “male” and “female” or “men” and “women” in this article reflects the language of the sources we’ve used. Unless otherwise noted, it’s unclear whether the research we reference included participants with expansive gender identities.

What you can do

If you notice symptoms of TD while taking Lybalvi, immediately contact your doctor. They may have you stop taking the drug.

But depending on the severity of the condition you’re taking Lybalvi to treat, they may have you continue treatment despite TD. In this case, your doctor may prescribe a medication to help ease the symptoms of TD. Examples include deutetrabenazine (Austedo) and valbenazine (Ingrezza).

Lethargy

Treatment with Lybalvi may cause lethargy as a side effect. Symptoms of lethargy include:

Lethargy can also cause changes in your mood.

What might help

Talk with your doctor if you’re feeling lethargic while taking Lybalvi. They can check for other possible causes of these symptoms. And they may recommend lifestyle modifications, such as:

If your lethargy is affecting your daily activities, your doctor may suggest you stop taking Lybalvi. If so, they’ll discuss other treatment options for your condition with you.

Get answers to some common questions about Lybalvi’s side effects.

What does Lybalvi do to the brain?

Lybalvi contains two active ingredients: olanzapine and samidorphan. It’s thought that olanzapine helps balance dopamine and serotonin levels in the brain. These are chemicals that help you regulate your mood and feel pleasure, and they may be involved in bipolar I disorder and schizophrenia. Samidorphan has effects on opioid receptors in the body.

Doctors may use the term “mood stabilizer” for medications that help regulate mood. However, Lybalvi is not a mood stabilizer. Exactly how Lybalvi works is not known for sure.

Your doctor or pharmacist can give you more information about Lybalvi’s effects on the brain.

How long do Lybalvi side effects last?

It varies. Some side effects, especially mild ones, may go away after a few days or weeks as your body gets used to Lybalvi. For example, sleepiness or nausea may lessen with time.

Other side effects may be longer lasting. For example, if you develop diabetes, blood cell problems, or tardive dyskinesia, these side effects can require long-term treatment. Other examples of possible long-term side effects include problems with regulating body temperature and neuroleptic malignant syndrome.

If you have questions about what to expect with Lybalvi’s side effects, be sure to talk with your doctor.

Will I experience side effects after stopping Lybalvi treatment?

Stopping treatment with Lybalvi isn’t expected to cause withdrawal symptoms. (These are side effects that can happen when you stop taking a drug that your body has become dependent on.) Dependence wasn’t reported in Lybalvi’s studies.

But since olanzapine (one of the active ingredients in Lybalvi) became available for use, certain withdrawal symptoms have been reported. Examples include nausea and vomiting as well as sweating. It’s not known for certain whether these side effects may occur after stopping Lybalvi.

And stopping Lybalvi treatment could cause a return or worsening of symptoms of the condition you’re taking the drug to treat. For example, schizophrenia symptoms may come back or worsen if you stop taking Lybalvi to treat that condition.

Talk with your doctor if you have questions about Lybalvi or would like to stop taking it. They can advise you on what to expect and tell you about other treatment options for your condition.

Does Lybalvi cause bleeding?

No, bleeding was not a side effect reported in Lybalvi’s studies.

A large review of older studies found that some antipsychotic drugs (Lybalvi is a type of antipsychotic) increase the risk of bleeding. But this study was conducted before Lybalvi was approved for use. So the study did not include Lybalvi or look specifically at the risk of bleeding with this drug.

If you have questions or are concerned about bleeding from Lybalvi, talk with your doctor or pharmacist.

Will Lybalvi affect my cholesterol levels?

It’s possible. Changes in cholesterol were a common side effect in Lybalvi’s studies.

Specifically, people taking Lybalvi in these studies were more likely to have an increase in their triglyceride levels. (Triglycerides are a kind of fat found in your blood.) Having high triglyceride levels can increase your risk of heart disease.

Talk with your doctor if you’re concerned about your triglyceride levels. They can tell you how they’ll monitor these levels while you’re taking Lybalvi. They can also discuss possible treatments for high triglycerides with you.

Before starting Lybalvi treatment, there are important considerations to keep in mind.

Lybalvi has a boxed warning. A boxed warning is the most serious warning from the FDA. For details, see the “Boxed warning for Lybalvi” section.

Other precautions

Lybalvi may not be right for you if you have certain medical conditions. These are known as drug-condition interactions. Other factors may also affect whether Lybalvi is a good treatment option for you.

Before starting Lybalvi, talk with your doctor about your health history. Be sure to talk with your doctor if any of the following apply to you:

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.