How Long Does It Take Zyprexa to Work? Plus 4 More Frequently Asked Questions

Zyprexa (olanzapine) is an atypical antipsychotic. It’s FDA approved for schizophrenia and bipolar disorder. It can also be prescribed with the antidepressant fluoxetine (Prozac) to treat bipolar depression and depression that hasn’t improved with other medications.

Zyprexa comes in a few different dosage forms. The oral tablet and orally disintegrating tablets (Zyprexa Zydis) are commonly prescribed. But Zyprexa is also available as fasting-acting and long-acting injections. The fast-acting injection can be given in hospital settings to help with agitation. The long-acting injection (Zyprexa Relprevv) is given every 2 to 4 weeks at a health clinic.

It’s common to have questions about your medication, especially if you’ve never taken it before. Below, we’ll answer five common questions about Zyprexa, including how long it takes to work.

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1. How long does it take Zyprexa to work?

This depends on the symptoms you have and the dosage form you’re taking. Oral Zyprexa may start relieving some symptoms right away. For instance, drowsiness is a common side effect of the medication. So if your mental health condition causes trouble sleeping (insomnia), Zyprexa may help with this after your first dose.

Oral Zyprexa may start working within 1 to 2 weeks for many other symptoms, including hallucinations, delusions, and lack of motivation. But it may take 2 to 3 months before you notice the full benefits of the medication.

The fast-acting Zyprexa injection starts working within 2 hours. But the long-acting injection takes about 1 week to fully enter your system. So there may be a delay in how fast it starts relieving symptoms compared to the oral forms.

2. How long does Zyprexa stay in your system?

Small amounts of oral Zyprexa and the short-acting injection stay in your system for around 6 days. But you won’t feel the effects of the medication for this long. Most people find that a dose wears off a little over a day later. That’s why many people take oral Zyprexa once a day.

The effects of the Zyprexa Relprevv injection last for about 30 days. But there may still be some amount of medication in your system for months after your last injection.

This is important to keep in mind when it comes to checking for drug interactions, and when considering other antipsychotic treatments. Zyprexa Relprevv could interact with other medications months after an injection. Make sure you include your most recent Zyprexa injection date on your medication list, so your healthcare team can check for interactions.

3. What’s the best time to take Zyprexa?

There is no “best” time for everyone when it comes to taking Zyprexa. But for many people, evening or bedtime works best.

Oral Zyprexa is typically taken once a day. Taking it around the same time each day helps provide steady amounts of medication to your body.

As discussed earlier, sleepiness is a common Zyprexa side effect. Taking your dose in the evening can help limit daytime drowsiness. While less common than drowsiness, insomnia is also a possible Zyprexa side effect. If this is the case for you, then a morning dose could be more helpful.

It’s best to avoid driving or performing activities requiring alertness right after taking Zyprexa until you know how it affects you.

4. Should you take Zyprexa with food?

Zyprexa can be taken with or without food. Food doesn’t change how the medication works in the body. If Zyprexa causes nausea or an upset stomach, try taking it with food. Taking your medication with the same meal each day is also a great way to remember your doses.

5. Does Zyprexa cause weight gain?

Yes, Zyprexa can cause weight gain. Compared to other antipsychotics, Zyprexa has one of the highest risks of weight gain. Studies have reported people gaining an average of 2 lbs per month with Zyprexa. About 1 in 3 people gained 7% or more of their starting body weight.

Over time, weight gain with antipsychotics can raise your risk of other health conditions, such as Type 2 diabetes and high cholesterol. If you’re gaining an uncomfortable amount of weight, speak with your healthcare provider.

Your provider may suggest:

• Making changes to your diet, such as including healthier foods and snacks that you like

• Exercising more often in a way that’s fun or feels good to you

• Switching to Lybalvi (olanzapine / samidorphan), a medication that contains both olanzapine (the active ingredient in Zyprexa) and a component that helps limit weight gain

• Discussing alternative antipsychotic medications with a lower risk of weight gain, such as Abilify (aripiprazole)

• Trying a medication that promotes weight loss if other tips aren’t helping enough

Tips on how to save on Zyprexa

There are many ways to save on Zyprexa, which is available as both a brand-name and generic medication.

• Save with GoodRx. GoodRx can help you save over 90% off the average retail price of the generic version. Generic Zyprexa’s price at certain pharmacies is as low as $13.20 with a free GoodRx discount.

• Save with patient assistance programs. If you’re uninsured or underinsured, you may be eligible for brand-name Zyprexa’s patient assistance program, which offers the medication free of cost. There’s also a patient assistance program available for the long-acting, injectable Zyprexa Relprevv.

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Written by:

Victoria Dadebo, PharmD, BCPS

Victoria Dadebo is a freelance pharmacy writer who began contributing to GoodRx in 2022. She has experience in both community and hospital settings, and she is furthering her pharmacy training to specialize in mental health.

Edited by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

Reviewed by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

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