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What to know about taking Tamiflu® for the flu

Published January 26th, 2023

As expected in the winter months, the flu virus spreads throughout our communities. Small children, the elderly, and immune compromised people are at higher risk for complications or serious illness from the flu, so it is important to know what tools are available to help treat it. Tamiflu can be an effective tool to treat the flu if taken early.

What is tamiflu?

Tamiflu (oseltamivir) is a prescription antiviral medication used to treat the influenza A & B viruses that cause the flu. It is an oral medication that is given in pill or liquid form for 5 days after testing positive for flu. It works by slowing the growth of the influenza virus.1

How do I get a prescription for Tamiflu?

To get a prescription for Tamiflu, you must test positive for the flu virus. If you have flu-like symptoms, including fever, body aches, chills, sore throat, cough, congestion, runny nose, headaches, and fatigue, you can get tested for the flu. At-home rapid flu tests are not currently available, so you need to visit a doctor to be tested and get a prescription. The test provided at the doctor’s office can also rule out infection with COVID-19 and RSV.

Tamiflu needs to be taken within 48—72 hours of the onset of these flu symptoms to be effective.1 Therefore, if you develop flu-like symptoms, it is important to get tested by your physician as soon as possible to ensure that you can start taking Tamiflu within this window.

What is the goal of tamiflu treatment?

The goal of treatment is to lessen the length of time that you are sick and reduce the severity of your symptoms.1 Tamiflu is not a cure for the flu. If you are not at risk for severe flu or complications, and you live with someone who is, you may consider taking Tamiflu.

Can Tamiflu Prevent me from catching the flu?

Tamiflu can be used to prevent patients from catching flu, but this is a less common use of the medication. A doctor may prescribe Tamiflu if a person who is at high-risk for serious illness lives in the same household as someone who has the flu.

The best way to prevent severe flu is to get your annual flu vaccine. Although the ideal time to get the vaccine is from mid-September through October, there is still a benefit to getting your flu shot in January or February, as the flu virus continues to circulate.

Who Can take Tamiflu?

  • Tamiflu is approved for treatment of flu symptoms in adults and children 2 weeks of age and older.
  • Tamiflu is approved for prevention of the flu in adults and children 1 year and older.
  • The CDC recommends that those who are pregnant or nursing be treated with an antiviral like Tamiflu if they have been infected with the flu.2

What are the side effects of Tamiflu?

  • Common side effects of Tamiflu include nausea and vomiting; these usually occur in the first 2 days and are typically not severe.1
  • Rare cases of allergic reactions may occur. Tamiflu may cause a life-threatening allergic reaction called anaphylaxis that requires immediate medical attention. If you or your child experience trouble breathing, trouble swallowing, hoarseness, itching of throat, swelling of hands, face, or mouth call your doctor right away. Less severe reactions including skin rashes, sores, skin peeling, or ulcers may occur. If you experience these reactions stop taking Tamiflu and call your doctor right away.



  1. TAMIFLU® (oseltamivir phosphate).
  2. CDC. Recommendations for Obstetric Providers for Use of Flu Antivirals. Centers for Disease Control and Prevention (2022).