COVID and flu home test: when to test, and how to read the results
We research products from makers' specs and health sources; we do not run hands-on tests. Links to Amazon may earn us a commission at no cost to you. How this works.
- BinaxNOW COVID-19/Flu A&B Combo Self Test. Best for: Checking COVID-19 and flu with one swab. See options on Amazon
- iHealth Flu A/B and COVID-19 3-in-1 rapid test. Best for: Households wanting several tests on hand. See options on Amazon
- Flowflex Plus RSV + Flu A/B + COVID home test. Best for: Adding RSV to the check. See options on Amazon
How at-home tests work
The FDA explains that at-home over-the-counter (OTC) COVID-19 diagnostic tests let you collect your own sample, perform the test and read the result yourself, without a prescription or sending a sample to a lab. Most are antigen tests, often called rapid tests, which detect proteins called antigens from SARS-CoV-2.
Antigen tests are less likely to detect the virus than molecular tests such as PCR, the FDA says, especially early in an infection or in people without symptoms. That is why the FDA authorizes all at-home COVID-19 antigen tests for repeat, or serial, testing.
When to test
- With symptoms: test immediately, then test again per the instructions if the first result is negative.
- After exposure, no symptoms: wait at least 5 full days after exposure before testing; testing too early may give an inaccurate result.
- Before seeing someone at high risk: the FDA suggests considering a test before contact with older adults, people who are immunocompromised or people with other medical conditions.
The FDA notes it may take 2 to 5 days, and sometimes longer, after exposure for an antigen test to detect the virus.
Reading a negative result
| If you tested negative and have | FDA guidance | Next test |
|---|---|---|
| Symptoms and an exposure | Assume you have COVID-19; take precautions | Again after 48 hours |
| Symptoms, no known exposure | You could still have COVID-19 or another illness | Again after 48 hours |
| No symptoms but an exposure | You could still have COVID-19 | Every 48 hours for 3 tests over 5 days |
| No symptoms, no exposure | Unlikely to have COVID-19 | Every 48 hours for 3 tests over 5 days |
From the FDA's guide to understanding at-home antigen results. For the symptomatic rows, the FDA also suggests considering a lab-based molecular test or calling your health care provider.
Reading a positive result
The FDA says a positive result on an at-home antigen test means you likely have COVID-19. Contact your health care provider and follow CDC guidance on staying home and away from people. Tests cannot tell you how contagious you are; the FDA notes you could pass COVID-19 to others even before you test positive.
The FDA encourages voluntarily and anonymously reporting your positive or negative results, for example through MakeMyTestCount.org or an app included with your test.
COVID and flu combo tests
A COVID-19 antigen test does not tell you whether you have another respiratory illness such as flu or RSV, the FDA says, unless the test is specifically authorized to detect those viruses. Combo tests sold for home use report COVID-19 and flu A and B together, and some add RSV. Read the box for which viruses a test covers and follow its instructions exactly, since timing and swab steps differ by brand.
Whatever the result, the FDA's guidance for COVID-19 applies: anyone who tests positive, or likely has the illness, should contact their health care provider, and people at higher risk should not wait to call.
Expiration dates and buying tips
- Check expiration. The FDA keeps a table of authorized at-home OTC COVID-19 tests, with links to instructions and notes on extended expiration dates. Search it by manufacturer or test name.
- Watch for counterfeits. The FDA has a page on counterfeit at-home COVID-19 tests; buy from established sellers.
- Keep enough tests for repeat testing: a negative result calls for at least two or three tests.
Pair testing with basic care tools; see our digital thermometer guide and pulse oximeter guide, and wash hands often; see our hand sanitizer guide.
What to look for when you buy
BinaxNOW COVID-19/Flu A&B Combo Self Test
Best for: Checking COVID-19 and flu with one swab
A combo test reports COVID-19 and flu A and B, which a COVID-only test cannot, per the FDA.
Watch out: Follow the repeat-testing instructions after a negative result.
See options on AmazoniHealth Flu A/B and COVID-19 3-in-1 rapid test
Best for: Households wanting several tests on hand
Multi-test boxes support the FDA's repeat testing after negatives.
Watch out: Check the expiration date before use.
See options on AmazonFlowflex Plus RSV + Flu A/B + COVID home test
Best for: Adding RSV to the check
The FDA says antigen tests only detect flu or RSV when specifically authorized for those viruses.
Watch out: Read the box for which viruses it covers.
See options on AmazonQuestions people ask
- Do I need to test again after a negative COVID test?
- Yes. The FDA says repeat after 48 hours: at least twice over three days with symptoms, three times over five days without.
- When should I test after exposure?
- Wait at least 5 full days after exposure if you have no symptoms, per the FDA.
- Does a COVID test detect the flu?
- Not unless it is specifically authorized for flu; use a combo test for both.
- What does a positive at-home test mean?
- The FDA says you likely have COVID-19; contact your provider and stay home.
- Can I use an expired COVID test?
- Check the FDA's table; some tests have extended expiration dates.
Sources
- Understanding At-Home OTC COVID-19 Antigen Diagnostic Test Results (fda.gov), U.S. Food and Drug Administration
- At-Home OTC COVID-19 Diagnostic Tests (fda.gov), U.S. Food and Drug Administration