Skip to Content

What is the difference between Xofluza and Tamiflu?

Medically reviewed by Last updated on Nov 22, 2018.

Official Answer


Xofluza and Tamiflu are both indicated for acute influenza (flu). Tamiflu is also taken as a flu preventive.

There are several differences between Xofluza (baloxavir marboxil) and Tamiflu (oseltamivir). Some of their main differences involve how they work, dosing, and cost.

Both of these drug are considered antivirals that work against the influenza virus, but they do this in different ways:

  • Xofluza works by blocking the cap-dependent endonuclease activity of the viral polymerase and prevents flu virus replication.
  • Tamiflu is a neuraminidase enzyme inhibitor that frees viruses from the infected cells surface.
  • Because Xofluza works with a new mechanism, theoretically it may be effective for viruses that have grown resistant to the antiviral action of Tamiflu.

What is the cost of Xofluza?

  • The new flu drug Xofluza costs $150 for one treatment, according to Genentech, the drug’s manufacturer. If you have prescription insurance, your plan will most likely cover the costs of at least one flu drug, minus your copay or coinsurance. Genentech is also providing a coupon for patients with commercial insurance to lower the cost of Xofluza to $30.
  • Tamiflu is now available as a more affordable generic drug called oseltamivir. The cost of oseltamivir is roughly $50 to $60 for 10 capsules of the 75 mg dose using online coupons at your pharmacy. The cost for one 60 mL bottle of the 6 mg/ml oral oseltamivir suspension costs about the same.
  • The brand name Tamiflu runs about three times the cost of the generic, about $180 cash with online coupons, but this price may vary.

How do the side effects differ between Xofluza and Tamiflu?

Side effects differ between Xofluza (baloxavir marboxil) and Tamiflu (oseltamivir), as well.

  • The most common side effects with Xofluza include diarrhea and bronchitis (lung inflammation).
  • The most common side effects of Tamiflu when used for treatment of the flu include nausea, vomiting, and headache.
  • When used for prevention of the flu, Tamiflu side effects may also include nausea, vomiting, headache, as well as pain.

How do the doses differ between Xofluza and Tamiflu?

The uses, doses and age ranges for Xofluza and Tamiflu are as follows:


  • Xofluza (baloxavir marboxil) is given as single-dose, oral treatment for acute, uncomplicated influenza in people 12 years and older. It should be taken within 48 hours of the start of flu symptoms, and is available as a tablet.
  • Do not take Xofluza with dairy products, calcium-fortified beverages, laxatives, antacids or oral supplements containing iron, zinc, selenium, calcium or magnesium due to possible drug interactions.


  • Tamiflu (oseltamivir) is also taken within 48 hours of flu symptom onset, but is taken twice a day for 5 days in a row to treat flu in people 2 weeks of age and older.
  • Tamiflu is also used as a flu preventive in people who are at least 1 year old and who may have been exposed to flu but do not yet have symptoms.
  • Tamiflu is available in an oral capsule formulation as well as a liquid suspension.
  • There is less chance of stomach upset if you take Tamiflu with food.

Related Medical Questions

Drug Information

Related Support Groups