Key takeaways:
Xofluza (baloxavir marboxil) is FDA approved to treat and prevent the flu in adults and children ages 5 and over. It’s taken as a single, one-time dose.
Calcium, iron, and magnesium can bind to Xofluza and make it less effective. Other minerals also have this effect. You should avoid foods and products that contain these ingredients the day you take Xofluza. Dairy products, antacids, and multivitamins are common examples.
Xofluza can make the FluMist nasal spray (live, attenuated flu vaccine) less effective if they’re taken together. A flu shot that’s inactivated won’t interact with Xofluza. But if you already have flu symptoms, it’s best to wait until you’ve recovered to get vaccinated.
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If you or a close contact develops the fever, chills, and muscle aches that signal influenza (the flu), your prescriber may recommend Xofluza (baloxavir marboxil). It’s an oral prescription medication that can help treat and prevent the flu in adults and children ages 5 and over.
You’ll take Xofluza as a single, one-time dose. But certain foods, medications, and supplements can lower Xofluza levels in the body and make it less effective. Knowing about Xofluza interactions in advance can help you get the most from this flu medication.
Xofluza interactions at a glance
Xofluza doesn’t have many interactions with other medications. But anything that contains calcium and other minerals can prevent your body from absorbing it. Below is a list of common Xofluza interactions to know about.
Xofluza interactions include:
Dairy products
Calcium-rich foods, such as greens and fortified breads or juices
Antacids that contain calcium, magnesium, or aluminum, such as Tums (calcium carbonate)
Laxatives that contain magnesium, such as Milk of Magnesia (magnesium hydroxide)
Multivitamins and supplements that contain minerals such as calcium, iron, and magnesium
Keep in mind that since Xofluza is a one-time dose, you can go back to your normal routine the day after taking it. If you’ve already eaten or taken one of the above products, wait 4 to 5 hours before taking Xofluza to avoid any issues.
Let’s take a look at each of these five Xofluza interactions in more detail.
1. Dairy products and calcium-rich foods
Calcium can bind to Xofluza and prevent your body from absorbing it. This can keep you from getting the full, effective dose. So it’s best to avoid high-calcium foods and drinks before and after taking Xofluza.
Most dairy products contain large amounts of calcium. This includes:
Milk
Cheese
Ice cream
Yogurt
Keep in mind that plant-based dairy products often have added calcium. So you should avoid them around the time of your Xofluza dose, too.
Other high-calcium foods include collard greens, black-eyed peas, and bok choy. And foods like breakfast cereals, breads, and juices are often fortified with calcium they wouldn’t contain naturally. So it’s a good idea to check the nutrition labels and avoid products that contain calcium the day you take Xofluza.
Since Xofluza is a one-time dose, you can go back to your regular diet the day after taking it. If you’ve already had a calcium-rich food or drink, it’s best to wait about 4 to 5 hours before taking Xofluza to prevent this interaction.
Xofluza side effects: Learn what side effects are possible while taking Xofluza (baloxavir marboxil) and how to manage them if they occur.
Medication alternatives: Discover simple home remedies that can help ease your flu symptoms naturally.
How does Xofluza work? Read answers to this and more common questions about Xofluza.
2. Antacids
Magnesium and aluminum can bind to Xofluza and prevent its absorption the same way that calcium can. And these are all common ingredients in over-the-counter (OTC) antacids, such as Tums (calcium carbonate) and Mylanta (aluminum hydroxide / magnesium hydroxide / simethicone).
It's best to avoid antacids the day you take Xofluza. If you have heartburn, histamine-2 antagonists (H2 blockers) such as Pepcid (famotidine) are OK to take, as they won’t bind to Xofluza. Proton pump inhibitors, such as Prilosec (omeprazole), are also a safe option. But avoid products like Pepcid Complete (famotidine / calcium carbonate / magnesium hydroxide) that also contain an antacid.
3. Laxatives that contain magnesium
Laxatives that contain magnesium can bind to Xofluza and make it less effective. So it’s best to avoid this combination. These products include Milk of Magnesia, magnesium citrate, and epsom salts (magnesium sulfate).
If you need constipation relief the day you take Xofluza, consider Colace (docusate sodium) or Senokot (senna). These won’t interfere with Xofluza’s effectiveness.
4. Multivitamins and supplements
You may take a daily multivitamin and/or supplements to support your overall health and well-being. But, like antacids and calcium-rich foods and beverages, they often contain calcium and other minerals that can bind to Xofluza and make it less effective.
It’s best to avoid taking multivitamins and supplements that have any of the following ingredients with Xofluza:
The supplement label is the best place to check for these ingredients. If you’re not sure if a product is safe to pair with Xofluza, don’t hesitate to ask your prescriber or pharmacist.
You can go back to your normal vitamin and supplement regimen the day after you take Xofluza. If you’ve already taken a product that contains one of these ingredients, it’s best to wait 4 to 5 hours before taking your Xofluza dose.
Good to know: Some OTC products that claim to help cold symptoms, such as Zicam, contain zinc. Even though they don’t work for the flu, people often take them anyway. But the zinc in these products can bind to Xofluza, so you shouldn’t take these products together.
5. Live flu vaccine
FluMist is a live, attenuated flu vaccine that comes as a nasal spray. It works by introducing a weakened form of the flu virus into your body. In response, your immune system makes antibodies that will help you fight off a real flu infection if you’re exposed to it in the future.
But if you take them together, Xofluza may kill the weakened virus in the FluMist vaccine before your body has a chance to respond to it. That could make the vaccine less effective.
If you’ve been exposed to the flu (but aren’t sick) and haven’t been vaccinated, it’s fine to receive the flu vaccine. Just choose one of the injectable options if you’re taking Xofluza the day of your vaccination. None of the available flu shots are live vaccines.
You shouldn’t receive any vaccines if you’re sick with the flu. But after you recover, it’s still a good idea to get your flu vaccine if you haven’t already done so. That’s because there’s more than one type of flu virus spreading every year during flu season.
Frequently asked questions
Alcohol doesn’t directly interact with Xofluza. But it’s generally best to avoid alcohol with Xofluza or while you have the flu. The combination can raise the risk of dehydration, worsen symptoms (such as nausea and headache), and delay your recovery.
Yes, it’s fine to take Tylenol (acetaminophen) along with Xofluza. There aren’t any interactions between these two medications. Just be sure to check for acetaminophen in any other OTC flu medication you’re taking first. It’s often included in these products to help with fever or headache from the flu. And taking more Tylenol than recommended can raise the risk of serious side effects.
You can take Xofluza along with OTC medications that help with flu symptoms. But you shouldn’t take Xofluza along with other prescription antivirals for the flu, such as Tamiflu (oseltamivir). Taking more than one antiviral for the flu isn’t likely to provide any added benefit, but it does raise your risk of unwanted side effects.
Alcohol doesn’t directly interact with Xofluza. But it’s generally best to avoid alcohol with Xofluza or while you have the flu. The combination can raise the risk of dehydration, worsen symptoms (such as nausea and headache), and delay your recovery.
Yes, it’s fine to take Tylenol (acetaminophen) along with Xofluza. There aren’t any interactions between these two medications. Just be sure to check for acetaminophen in any other OTC flu medication you’re taking first. It’s often included in these products to help with fever or headache from the flu. And taking more Tylenol than recommended can raise the risk of serious side effects.
You can take Xofluza along with OTC medications that help with flu symptoms. But you shouldn’t take Xofluza along with other prescription antivirals for the flu, such as Tamiflu (oseltamivir). Taking more than one antiviral for the flu isn’t likely to provide any added benefit, but it does raise your risk of unwanted side effects.
The bottom line
Xofluza (baloxavir marboxil) is an antiviral medication that’s taken as a single, one-time dose to treat or prevent the flu. Calcium, magnesium, and other minerals can bind to Xofluza and make it less effective. So it's best to avoid foods, medications, and supplements that contain them the day you take Xofluza. This includes dairy products, antacids, and multivitamins.
Xofluza can also prevent FluMist (the live, attenuated flu vaccine) from working properly. A flu shot that’s inactivated won’t interact with Xofluza. But if you already have flu symptoms, it’s best to wait until you’ve recovered to get vaccinated.
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References
National Center for Complementary and Integrative Health. (n.d.). 5 tips: Natural products for the flu and colds: What does the science say?
Sportpharm doing business as Sportpharm. (2025). Xofluza- baloxavir marboxil tablet, film coated [package insert].
World Health Organization. (n.d.). Food fortification.
