COVID Testing: Timing, Delivery, and Expiration - Your Complete Guide

A new study suggests that the viral load of COVID-19 is highest four to five days after symptoms appear, indicating that at-home antigen tests may not be effective if taken too early. Testing on the first day of symptoms could result in a false negative due to lower viral load. PCR tests are generally considered more reliable than at-home tests, as they can detect lower levels of viral load. If experiencing symptoms and receiving a negative antigen test, it is recommended to wait 48 hours and retest or opt for a PCR test. Regardless of test results, it is important to isolate when experiencing respiratory illness to prevent the spread of any potential virus.