Zyprexa (Olanazapine) - Oral

Mental health professional prescribing medication

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Zyprexa (olanzapine) is an atypical antipsychotic medication used in the treatment of bipolar disorder, schizophrenia, and treatment-resistant depression. It can be used for new onset of disease and long-term maintenance of schizophrenia. For bipolar disorder, it is considered a first-line therapy for acute mania.

Side effects with Zyprexa are possible (as with most medicines), but its benefits may outweigh the side effects for you. Before you decide if Zyprexa is the best choice for your needs, learn more about how it is used, the potential side effects, and any precautions you should consider.

What Is Zyprexa?

Zyprexa is FDA-approved for the treatment of schizophrenia, for manic and mixed episodes associated with bipolar I disorder, and for maintenance treatment of bipolar I disorder. It is also approved as an adjunct to valproate or lithium in the treatment of bipolar I disorder. Zyprexa is also approved for use in combination with Prozac (fluoxetine) for treatment-resistant depression.

How to Take Zyprexa

Zyprexa is taken by mouth, usually once per day. It can be taken with or without food. In most cases, your doctor will start you on a low dose of the medication and assess your response before gradually increasing your dose until optimal effects are achieved.


Zyprexa should be kept in a closed container out of the reach of children. It should be stored at room temperature and kept away from direct light, heat, moisture, and freezing temperatures. 

Off-Label Uses 

While atypical antipsychotics such as Zyprexa are used primarily to treat schizophrenia and bipolar disorder, they are also sometimes prescribed for other purposes. For example, they may be prescribed off-label for symptoms such as agitation, obsessive behaviors, and psychotic episodes.

What Are the Side Effects of Zyprexa?

In addition to its benefits for schizophrenia, bipolar disorder, and depression, Zyprexa can also sometimes result in unwanted side effects. Not everyone experiences all of these side effects and they may vary in terms of severity.

Black Box Warning

Zyprexa is not approved for older adults with dementia-related psychosis, as the drug can increase the risk of death in this population by 60% to 70%. The FDA placed a black box warning on all antipsychotics (atypical and typical) due to this increased mortality risk.

Common Side Effects

Common side effects of Zyprexa include:

  • Dizziness
  • Dry mouth
  • Hard or infrequent stools
  • Increased appetite
  • Lack of energy
  • Sleepiness or excessive sleeping
  • Tremor
  • Weight gain

Be sure to consult your doctor if any of these side effects bother you or persist. Your doctor may be able to adjust your dose to help minimize these side effects.

It's important to note that there are also some unique side effects that teenagers may experience with Zyprexa, so be sure to review these with your doctor. Adolescents may be more likely to experience weight gain and hyperlipidemia (a condition where there are high levels of lipids in the blood).

Severe Side Effects

One common and possibly serious side effect of Zyprexa is significant weight gain, which has been reported as one of the top reasons people choose to stop taking the medication. It's important to note that weight gain is also dose-dependent—the higher your dosage, the more weight you are likely to gain.

In addition, Zyprexa can increase blood sugar levels, putting a person at risk for developing diabetes. Zyprexa may also increase an individual's cholesterol levels.

All three of these factors combined—weight gain, high blood sugar, and high cholesterol—can increase the patient's risk of heart disease, which is why it's important to review an exercise and nutritional plan with your doctor while on Zyprexa.

Other serious side effects of Zyprexa can include:

  • Heat sensitivity: You also may be more sensitive to heat. So be sure to drink plenty of water, especially in hot weather or before and after exercising.
  • Seizures: Zyprexa can lower the seizure threshold, though this is a rare occurrence.
  • Dysphagia: Problems swallowing may occur.
  • Orthostatic hypotension: This is dizziness or fainting when going from sitting to standing due to low blood pressure.

Long-Term Side Effects

Zyprexa may also lead to other long-term side effects including:

  • Neuroleptic malignant syndrome (NMS): Signs include muscle rigidity, confusion, high fever, alterations in blood pressure and heart rate, and abnormal heart rhythms.
  • Stroke: An increased risk of strokes in older adults with dementia-related psychosis also exists.
  • Tardive dyskinesia: Condition that can occur with the long-term use of antipsychotics that causes repetitive, involuntary movements, though the risk of tardive dyskinesia on Zyprexa is lower when compared to typical or first-generation antipsychotics. While sometimes reversible, this side effect is permanent in some cases.

How Much Zyprexa Should I Take?

Zyprexa is available as 2.5, 5, 7.5, 10, 15, and 20 mg tablets. It is also available in 5, 10, 15, and 20 mg orally disintegrating tablets.

The starting dose is usually 5 to 10 mg, and dosages are usually increased in 5 mg increments with a minimum of a week between dosage adjustments. Clinical trials suggested that an effective dose in the treatment of schizophrenia was between 10 and 15 mg per day. The maximum indicated dose is 20 mg a day.

All listed dosages are according to the drug manufacturer. Check your prescription and talk to your doctor to make sure you are taking the right dose for you.


For children between the ages of 13 and 17, the typical starting dose is 2.5 to 5 mg per day. 

When used in conjunction with Prozac for the treatment of depression, the starting dose is 5 mg of Zyprexa and 20 mg of Prozac once each day, usually taken in the evening. This dosage may be adjusted as needed, with a maximum dose of 18 mg of Zyprexa and 75 mg of Prozac per day

Older adult women may metabolize Zyprexa more slowly, which means that their dosage should be modified to account for this. People who have a predisposition to hypotensive reactions should also be started at a lower dose and carefully monitored when increasing the dosage.

Missed Dose

When on Zyprexa, try and take it at the same time every day. If you accidentally forget a dose, take it as soon as you remember—unless it's almost time for the next dose anyway. Then skip it, and take your regular dose as scheduled. Do not take two doses of Zyprexa at the same time. If you are unsure about your timing, call your doctor to be safe.

What Happens If I Take Too Much Zyprexa?

Taking too much Zyprex can lead to an overdose. Symptoms of an overdose may include:

  • Blurred vision
  • High fever
  • Low blood pressure
  • Rapid heartbeat
  • Slowed breathing
  • Sleepiness
  • Unusual and uncontrollable movements
  • Seizures

If an overdose is suspected, call your doctor or 911 immediately.


There are also important warnings and precautions to be aware of before taking this medication. Zyprexa increases the risk of death due to cerebrovascular events in older adults with dementia-related psychosis. 

Zyprexa also increases the risk for leukopenia, neutropenia, and agranulocytosis, which involve low white blood cell counts. Because of this, people with a history of low white blood cell count should be carefully monitored, and the use of the medication should be discontinued if white blood cell counts decrease.

Because this medication may pose a risk to the unborn fetus, Zyprexa should only be used during pregnancy if the potential benefits outweigh the risks. Zyprexa is not recommended for breastfeeding mothers. The safety of this medication for children under the age of 10 has not been established.

What Are Reasons I Should Not Take Zyprexa?

You should also not take Zyprexa if you have: 

  • Breast cancer
  • Cardiovascular conditions
  • Dementia
  • Diabetes
  • Glaucoma
  • High cholesterol
  • Liver problems
  • Low blood pressure
  • Parkinsonism
  • Tardive dyskinesia

It is important to give your doctor a complete medical history, including all your medical problems and allergies. Some people should not take Zyprexa or should only take it with caution. For example, tell your doctor:

  • If you are lactose-intolerant; Zyprexa tablets contain lactose
  • If you drink alcohol; alcohol should be used cautiously if at all when taking Zyprexa
  • If you are breastfeeding; there may be potential risks that you should discuss with your doctor

What Other Medications Interact With Zyprexa?

You'll want to share with your doctor all the medications you take including prescription medication, herbals, vitamins, and any over-the-counter medications. Some medications interact with Zyprexa and may cause serious side effects or require that your doctor change your dose.

Substances that may cause interactions when taken with Zyprexa include:

  • Alcohol
  • Anticholinergic drugs
  • Antihistamines
  • Tegretol (carbamazepine)
  • Valium (diazepam)
  • Levodopa and dopamine agonists
  • Luvox (fluvoxamine)
  • Prescription pain medications 
  • Prilosec (omeprazole)
  • Rimactane (rifampin) 

You should also never start or stop Zyprexa without seeking the advice of your doctor.

What Medications Are Similar?

Other antipsychotic medications that may be prescribed to treat schizophrenia or bipolar disorder include new antipsychotics such as:

  • Abilify (aripiprazole)
  • Clozaril (clozapine)
  • Geodon (ziprasidone)
  • Risperdal (risperidone)
  • Saphris (asenapine)
  • Seroquel (quetiapine)

Older antipsychotics may also be prescribed. These include:

  • Haldol (haloperidol)
  • Prolixin (fluphenazine)
  • Thorazine (chlorpromazine)

How Can I Stay Healthy While Taking Zyprexa?

Always be sure to take your medication as directed by your prescribing physician. Since you may experience some dizziness and drowsiness while taking this medication, you should avoid driving or similar activities until you know how Zyprexa will affect you. 

When you are taking Zyprexa, you may need to periodically have your cholesterol, triglyceride, and blood sugar levels tested. 

You should be sure to drink plenty of fluids while taking Zyprexa. Avoid becoming overheated, such as during hot weather or while exercising.

Be sure to avoid alcohol or drugs while taking Zyprexa, since they may interfere with your medication and increase the risk of side effects.

Frequently Asked Questions

  • How long does it take for Zyprexa to work?

    It takes around a week for Zyprexa to reach a steady state in the body. You may start to notice some effects after a couple of weeks, including improvements in symptoms such as disorganized thinking, delusions, and hallucinations. It may four to eight weeks to begin to experience the full effects of the medication.

  • How does Zyprexa work?

    Zyprexa is a second-generation antipsychotic, also often referred to as an atypical antipsychotic. It works by helping to balance the levels of dopamine and serotonin in the brain, which can improve thinking, behavior, and mood.

  • How much does Zyprexa cost?

    The cost of Zyprexa varies depending on a number of different factors. The average retail price is almost $163, however, it is often covered by insurance and generic forms are also available. Other ways to save on your prescription include checking for manufacturer or pharmacy coupons, ordering a 90-day supply of your medication, or using a lower-cost alternative.

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Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Marcia Purse
Marcia Purse is a mental health writer and bipolar disorder advocate who brings strong research skills and personal experiences to her writing.