Everyday Prevention

When should I take a rapid test and how well do they work?

Sasha Baumann
Published: January 7, 2022

Rapid tests (also called antigen or point-of-care tests) are quick and easy-to-use options for COVID-19 testing, though they are a bit less accurate than molecular tests like PCR or LAMP tests. Rapid tests can be done at home by swabbing your own nose and provide results within 30 minutes. Over 25 rapid tests are authorized for use by the FDA, and some of these can be used at home. Common brand names of rapid tests include Abbott BinaxNOW, QuickVue, InteliSwab, LumiraDx, and CareStart.

How accurate are rapid tests? 

Rapid tests may miss some COVID infections and work best on people who have symptoms. A review of 24,000 samples found that rapid tests were 72% accurate at identifying COVID infection among symptomatic people and 58% accurate among asymptomatic people. This means that 2 in 5 people with COVID who don’t have symptoms may get a false negative result. 

That said, rapid tests have less than 2% chance of a false positive result. So if your rapid test comes back positive, it is very likely you have COVID. 

How soon should I take a rapid test? 

You should take a rapid test 5 to 7 days after an exposure for best results. And a negative rapid test result is only good for about 12 hours, so they should be taken as close to an event as possible. 

When should I use a rapid test? 

Rapid tests are most useful in the following situations: 

  1. To screen people every day or every couple of days at work or school. 
  2. To test guests right before a gathering or event. 
  3. To gain entry into a country while traveling.
  4. To confirm infection if you have symptoms of COVID-19 after an exposure.*

*If you have symptoms of COVID-19 and your rapid test comes back negative, you should take a molecular test like a RT-PCR or PCR to confirm infection. 

Where can I get a rapid test? 

Rapid test kits typically cost between $5 and $50 and, when supply is not limited, are available at most pharmacies in the United States. You can read more from COVID-101 here about where to find a free test. 

Last update: 5 January 2021, 18:00 EST

Science review: ERS