Home use tests for COVID-19 test a nasal swab sample or saliva for the presence of the virus that causes COVID-19. A home use test can be used by people in the home, workplace or elsewhere without the involvement of a doctor or health practitioner. Most home use tests produce a result within 10-20 minutes. The tests are most reliable when used by a person who has symptoms of COVID-19. They are not as reliable when used to test someone who does not have symptoms.