Why 48 hours?
Act fast to fight back against flu

Many studies have shown that antiviral flu medications work best when you take them within 48 hours of developing flu symptoms.1
Get better, faster

Taking an antiviral flu treatment within two days (48 hours) of developing symptoms offers the best results to ease its severity and shorten your illness.1 By acting quickly, you can give your body the very best chance to start getting better.

The most important thing is to talk to your doctor or healthcare provider as soon as you suspect you might have flu. They’ll then be able to recommend the best treatment plan for you.

Stages of flu

Flu can occur in stages, and it can be helpful to understand these stages so that you know when is the best time to talk to your doctor:


Stage 1

The first signs of flu often include a fever and aching muscles, along with a headache, sore throat and extreme tiredness.2

Unlike a cold, early flu symptoms usually come on very suddenly, with little warning.3,4

This is the best time to speak to your doctor about flu medications.

Stage 2

Most symptoms tend to improve within one week, but coughing and tiredness may last longer.2 You’ll probably have to put your daily routine on hold while you rest in bed.


Stage 3

As long as no complications develop, you’ll start to feel a little better after a few days as your body (and the antiviral medication) fights back against the flu virus.4 However, you may continue to feel tired for some time.4

How long does flu last?
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Flu usually lasts between one and two weeks, but symptoms and recovery times can vary dramatically from one patient to another.5

Complications can make the illness last much longer and could result in hospitalization, or even death, in the most severe cases.6,4

Remember, you can be contagious and spread flu to others even before you begin to feel the first flu symptoms.5

There are a lot of myths about flu, its treatment and prevention. Click here to separate the fact from the fiction

Think you’ve got flu? Visit your doctor to discuss if an antiviral flu medication might be right for you

If you get sick this flu season, it’s important to speak to your doctor or healthcare provider as soon as possible.


Find out more about flu in your local area using the CDC influenza map.


  1. Lehnert R et al. Dtsch Arztebl Int 2016; 113(47): 799–807.
  2. Institute for Quality and Efficiency in Health Care (IQWiG). Flu: Overview, 2016. Available from https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0072643/#i2352.symptoms Last accessed October 2018.
  3. Banning M. Br J Nurs 2005; 14(22): 1192–1197.
  4. Centers for Disease Control and Prevention. Flu Symptoms & Complications, 2018. Available from https://www.cdc.gov/flu/consumer/symptoms.htm Last accessed October 2018.
  5. Centers for Disease Control and Prevention. Morbidity and Mortality Weekly Report, 2008; 57: RR-7. Available from https://www.cdc.gov/mmwr/pdf/rr/rr5707.pdf Last accessed October 2018.
  6. Mertz D et al. BMJ 2013; 347: f5061.
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Date of preparation: November 2018

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