What To Know About Zulresso (Brexanolone)

An Antidepressant Used to Treat Postpartum Depression

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Zulressso (its generic name is brexanolone) is an antidepressant specifically designed to treat postpartum depression (PPD) in adult women. It is administered under medical supervision as an infusion, typically over a 60-hour time frame. It belongs to a class of drugs known as neuroactive steroid gamma-aminobutyric acids (GABAs).

Zulresso is available as a solution for intravenous infusion, and its active ingredient is brexanolone.

Zulresso is currently only available through a program called Zulresso Risk Evaluation and Mitigation Strategy (Zulresso REMS).


Zulresso is the first drug to be approved by the FDA specifically to treat symptoms of postpartum depression in adult women. Postpartum depression is a common condition that affects women of all ages across the world.

Research shows that as of 2012, about 11% of women in the United States were living with postpartum depression.

Postpartum depression is a mental condition that occurs after childbirth. It causes a person who has it to experience recurring feelings of sadness and emptiness that can interfere with their daily lives and parenting.

In a 2019 study on the effectiveness and safety of Zulresso, researchers found that, when Zulresso was administered as an infusion over 60 hours to participants with moderate or severe postpartum depression, they experienced a significant reduction in depression scores as compared to those who were given a placebo.

Before Taking 

You can only access Zulresso through a program called Zulresso Risk Evaluation and Mitigation Strategy (Zulresso REMS). You must register for the program before this medication can be administered to you. This is because of the risk of excessive sedation and loss of consciousness associated with using this medication.

Healthcare facilities that wish to administer Zulresso are also required to enroll in the program and ensure that patients to which Zulresso is administered are also enrolled in the program. 

Patients with renal diseases, especially end-stage renal disease should avoid using Zulresso.

According to the manufacturer, no contraindications with other medication have been reported while using Zulresso.

Nevertheless, it is important to disclose to your doctor any other medication, vitamins, and supplements you are using before taking Zulresso or any other new medication. 

Before taking Zulresso, you should also tell your healthcare provider if you have a history of alcoholism, any kidney problems or if you are pregnant. There is no indication that Zulresso will adversely affect your baby, but it’s wise to disclose this to your medical doctor to guide your dosage options. Zulresso is not approved for anyone who is under the age of 18. 

Allergic Reactions

In rare cases, some people might experience an allergic reaction when using Zulresso. Symptoms of an allergic reaction include a rash or hives, difficulty breathing, swelling of the throat, tongue, or face.


Zulresso is administered as a continuous intravenous infusion by a medical professional, over a total of 60 hours, which is roughly two-and-a-half days.

A pulse oximeter is used to check your pulse during the period of infusion to monitor for hypoxia—a condition in which the tissues in your body become deprived of adequate oxygen.

Here is how the dosage is broken down over the 60-hour period

  • 0 to 4 hours: Dosing is started at 30 micrograms (mcg) per kilogram (kg) every hour 
  • 4 to 24 hours: Dosing is increased to 60 mcg per kg every hour
  • 25 to 52 hours: If the medication is being well tolerated, dosing may be increased to 90 mcg per kg every hour 
  • 52 to 56 hours: Dosing starts to be reduced and is brought down to 60 mcg per kg every hour
  • 56 to 60 hours: Dosing is further decreased to 30 mcg per kg every hour


One of the side effects you might experience while using Zulresso is excessive sedation. If your doctor notices you are excessively sedated at any point during the infusion they might pause the medication until your symptoms pass. When the infusion is resumed they might lower the dosage. 

How to Take and Store

Zulresso is supplied as a concentrated solution in vials to certified healthcare facilities in the Zulresso REM program. This solution is required to be diluted before being administered to patients.

After it has been diluted, the medication is transferred to infusion bags and can be stored in refrigerated rooms for up to 96 hours. If stored at room temperature, the medication will only be viable for 12 hours. The medication is administered through an intravenous tube and must not be combined with any other medication in the same infusion bag. 

An unopened vial of the concentrated solution can be stored at room temperature away from direct sunlight. A diluted bag can either be refrigerated or stored at room temperature, albeit for a shorter period than if refrigerated.

Before administration, the vial should be closely inspected. If there are any signs of discoloration or the presence of any other matter in it, then it should be carefully disposed of. Five infusion bags are typically prepared for the 60-hour period it takes to administer the medication.

Side Effects

Zulresso has been linked to some side effects in women. While some are mild and tend to dissipate with time, others can be more severe and could call for discontinuation of the medication.


Some common side effects you might experience when using Zulresso include: 

  • Headache 
  • Dizziness 
  • Sedation
  • Flushed skin
  • Dry mouth 


In rare cases, some people might experience more severe side effects while using Zulresso. Some include: 

  • Loss of consciousness 
  • Excessive sedation 
  • Suicidal thoughts
  • Irregular heartbeat

Warnings and Interactions 

When using Zulresso, you might experience excessive sedation or sudden loss of consciousness during infusion. There is also an increased risk of experiencing suicidal thoughts when using Zulresso.

If you or someone you know is receiving Zulresso, look out for changes in moods and behaviors. Tell your healthcare provider immediately if you notice any of these symptoms.

If Zulresso is administered alongside depressants such as opioids and benzodiazepines, you might experience an increase in the likelihood of adverse reactions like excessive sedation. 

Research shows that with breastfeeding women, the medication can be transferred into the breastmilk. However, the amount of medication that transfers into the breastmilk is low and there has been no indication of it affecting a breastfed baby adversely. 

The active ingredient in Zulresso is brexanolone which is a schedule IV controlled substance. This means that it has the potential to be abused or for a dependency on the medication to develop.

7 Sources
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.
  1. Ko JY. Trends in Postpartum Depressive Symptoms — 27 States, 2004, 2008, and 2012. MMWR Morb Mortal Wkly Rep. 2017;66.

  2. Leader LD, O’Connell M, VandenBerg A. Brexanolone for postpartum depression: clinical evidence and practical considerations. Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy. 2019;39(11):1105-1112.

  3. U.S. Food and Drug Administration. FDA approves first treatment for post-partum depression. March 19, 2019

  4. Azhar Y, Din AU. Brexanolone. In: StatPearls. StatPearls Publishing; 2020.

  5. Michigan Medicine, University of Michigan. Brexanolone. January 8, 2020

  6. Dacarett-Galeano DJ, Diao XY. Brexanolone: a novel therapeutic in the treatment of postpartum depression. American Journal of Psychiatry Residents’ Journal. 2019;15(2):2-4.

  7. U.S. National Library of Medicine. Zulresso- brexanolone injection, solution. December 14, 2020

By Toketemu Ohwovoriole
Toketemu has been multimedia storyteller for the last four years. Her expertise focuses primarily on mental wellness and women’s health topics.