What You Should Know About At-Home Covid-19 Testing Kits

How effective and reliable are they?

Gloria Oh
Medium Coronavirus Blog
4 min readNov 6, 2020


Credit: Circle Creative Studio / Getty Images

Costco recently announced it is selling direct-to-consumer Covid-19 testing kits (currently available online only) that allow users to take the diagnostic test from the comfort of their home. Consumers can choose between two options: a basic saliva testing kit for $129.99 or the same kit plus additional video support instructions for $139.99.

The wholesale discount giant now joins a growing list of supermarket retailers, including Vons, Albertson’s, and Safeway, that are selling at-home Covid-19 saliva testing kits — a trend that may continue as companies race to bring more rapid home tests to the marketplace. It’s worth noting that other grocery stores and pharmacies, including Kroger, Rite Aid, CVS Health, and Walgreens have been offering free Covid-19 testing clinics directly on-site, which is different from selling at-home testing kits.

Here are some factors that consumers should consider and be aware of before buying an at-home kit:

How accurate is the test?

Costco’s saliva PCR test is FDA authorized and received an Emergency Use Authorization to be used at home, in offices, or a pharmacy setting.

The official name of the test is P23 Labs TaqPath SARS-CoV-2 Assay and is administered by Azovo, a telehealth platform. According to Azovo, the saliva test has a sensitivity of 98% (where 98% of positive tests are correct) and a specificity of 99% (that is, 99% of negative tests are correct).

PCR tests are considered the gold standard coronavirus testing method on the market. According to Nature, “[s]tandard RT-PCR tests for the coronavirus take between one and four hours and can be up to 100% accurate — although the accuracy of any diagnostic test depends on many factors, such as when in the course of infection a sample was taken.”

In general, customers should ensure that any at-home testing kit they purchase is FDA-approved.

Read more on the efficacy of at-home saliva tests for Covid-19:

How it works and when to expect results

Customers first need to complete an online health assessment before the kit is mailed out. Once the kit is received, customers spit into a test tube and send in their saliva sample in a pre-provided package that is shipped back to the lab. Customers can expect results within 24 to 72 hours after the lab receives the sample. This timeframe places it on par with what most health care providers offer with drive-thru Covid-19 testing sites.

Pros of at-home Covid-19 testing kits

  • Convenience: Consumers who purchase an at-home kit do not have to set up an appointment with a health care system. This might save time and free up the logistics of setting up an in-person appointment and commuting to a testing site.
  • Benefits those living in rural or remote areas where it may be difficult to access a Covid-19 testing facility center.
  • Avoiding in-person visits if you’re at risk, thereby reducing the risk of spreading the virus or getting infected.
  • Comfort factor: Avoiding deep nasal swabs, which are more invasive and uncomfortable.

Cons of at-home Covid-19 testing kits

  • Cost: Many critics are wary about companies trying to commercialize a test that should be free. Back in March, the federal government passed the Families First Coronavirus Response Act that provided funds to “reimburse the costs of providing Covid-19 diagnostic testing and services to individuals without health insurance.”
  • It’s not guaranteed that direct-to-consumer tests will be reimbursed. For example, Costco’s product page says their tests are FSA eligible, but will other private companies also offer comprehensive guidance on coverage if they’re not required to do so?
  • Gaps in data reporting: At-home testing kits raises questions about what impact direct-to-consumer testing kits, and rapid tests in general, will have on nationwide contact tracing efforts. “The Centers for Disease Control and Prevention website has race and ethnicity data only for half of Covid-19 cases,” STAT reports.
  • More possibility for consumer fraud and scam. How to avoid that:

Further reading

Business Insider tracked a running list of direct-to-consumer coronavirus tests, which you can read more about here:



Gloria Oh
Medium Coronavirus Blog

Senior Editor, Medium. Founding Editor of Index. Previously, The Atlantic.