Let’s talk about Tamiflu

Yes, it can make a difference if you have the flu. No, it doesn’t treat or prevent the coronavirus.
By:
Feb. 11, 2025
a woman rests on a couch. She uses a kleenix to blow her nose. Photo: Getty Images.
Tamiflu is prescribed after a flu diagnosis. People who are sick need to take Tamiflu early in the course of their illness. The antiviral medication does not work for COVID-19. Photo: Getty Images

Flu season is upon us, and it’s shaping up to be a rough one.

The most important thing you can do to protect yourself is to get a flu shot. But if you end up with the flu, and you get it diagnosed quickly, there are antiviral treatments that have been shown to help with symptoms and, if taken soon after symptom onset, shorten the flu’s length by a day or two. The best-known of them is Tamiflu (or, as a generic, oseltamivir phosphate). The U.S. Food and Drug Administration approved the Roche-developed drug, which is taken in pill or liquid form, back in 1999.

How does Tamiflu work?

Tamiflu – which, like other antivirals, is available only with a prescription – hinders the flu virus’s ability to replicate and multiply. Fewer viruses can mean lesser symptoms and a shorter duration of disease. That’s especially important for those who are older or immunocompromised who are at a much higher risk of developing pneumonia and ending up hospitalized, says Dr. Michelle Barron, UCHealth’s infectious-disease specialist. Further, the CDC notes studies that have reported early antiviral treatment to reduce the risk of death among such patients.

When do you take Tamiflu?

As soon as possible after diagnosis, ideally within 48 to 72 hours of symptom onset.

Does Tamiflu work for COVID-19?

No. Different viruses have unique characteristics that different antivirals target. Taking Tamiflu for a COVID-19 infection would be like using a bear trap to catch a shark. But there are antivirals for COVID-19. If you’re sick, get tested to figure out which illness you have. If you have COVID-19, your doctor might prescribe an antiviral called Paxlovid.

What other flu treatments are out there?

According to the U.S. Centers for Disease Control and Prevention, there are four approved flu antivirals: Tamiflu, zanamivir (trade name Relenza), peramivir (trade name Rapivab), and baloxavir marboxil (trade name Xofluza). Zanamivir is a powder that’s inhaled and, like Tamiflu is typically taken for five days. Peramivir is given once intravenously. Baloxavir is a single-pill dose.

Dr. Michelle Barron, the top infectious disease expert in Colorado.
Dr. Michelle Barron gives advice about avoiding the flu and taking Tamiflu if you do get sick. Photo by Cyrus McCrimmon, for UCHealth.

What’s the best way to avoid getting the flu and to avoid needing Tamiflu?

Barron’s answer is simple. Protect yourself from the flu, and then you won’t feel lousy, and you won’t need to ask your doctor to prescribe Tamiflu.

“I just encourage everybody to get their flu shot,” Barron says. “The value of getting a flu shot is that you probably won’t need Tamiflu and you don’t have to come in and get tested.”

coronavirus flu season Infection prevention influenza

About the author

Todd Neff has written hundreds of stories for University of Colorado Hospital and UCHealth. He covered science and the environment for the Daily Camera in Boulder, Colorado, and has taught narrative nonfiction at the University of Colorado, where he was a Ted Scripps Fellowship recipient in Environmental Journalism. He is author of “A Beard Cut Short,” a biography of a remarkable professor; “The Laser That’s Changing the World,” a history of lidar; and “From Jars to the Stars,” a history of Ball Aerospace.