President Biden says people will soon be able to get free, at-home COVID tests as part of his plan to combat the virus, but just how reliable are those tests.

Like a lot of pharmacists, Wael Isaac offers COVID testing to customers.

Isaac also sells two brands of at-home COVID tests, which promise results in minutes, but can those results be trusted?

"Some brands of the at-home tests, they give false positive results, so we don't recommend it too much for people," says Isaac.

In late November, the FDA announced a phase one recall, the most serious kind, of two million Ellume home COVID tests.

The agency says the tests gave an unacceptable number of false positives. Only certain lots were affected, and the test is one of over a dozen home tests approved by the FDA.

Team 12 checked out three of the top selling home COVID tests. They're all pretty easy to use--you take a swab from your nostrils and the test looks for small viral proteins called antigens. The good news--you'll get results in as little as 15 minutes instead of days for a lab test. However, the lab tests are nearly 100% accurate, home tests don't come close.

In clinical trials, the best-selling home test, Abbott's Binax Now, detected the virus 84.6% of the time.

Another top seller, the Quidel Quickvue, caught 83.4% of COVID cases.

In fact, experts say we can expect home COVID tests to be about 85% accurate. That may sound good until you consider that on average, for every 100 people with COVID take a home test, 15 will wrongly get told they are not infected.

"If you are symptomatic, then that's really where the at-home tests again, which are less sensitive, aren't your best option," says Dr. Shereef Elnahal, president of University Hospital in Newark.

Elnahal says if you think you might have COVID, don't trust a home test. Go the extra mile and use a test that's processed by a lab.

"The risk of missing a positive test can be a risk to you, but also for the population. Making sure you do that PCR test when you have symptoms is really important," says Elnahal.

Team 12 also uncovered research that found that in the real world, home tests aren't as accurate as clinical trials indicate.

Isaac believes that's because getting accurate results is harder than it looks.

"The technique of taking the sample, it's not like a technician doing 100 samples every day," says Isaac. "So, I try to do it myself, from my nose, and when I stick it, I don't take the sample because I'm afraid."

Team 12 asked Isaac whether he thinks people won't go in far enough?

"Yes, they don't take the right position for the sampling," says Isaac.

So, when are home COVID tests recommended?

Elnahal says they're great for routine screening, like before traveling, attending a large event, or visiting an elderly relative.

"In other words, it's a little bit lower of a risk," says Elnahal. "You know, the implications of missing a test wouldn't be that dire."

There's one other group of people who should be careful with home COVID tests--people with color deficient vision. With this test, the difference between a negative and inconclusive result comes down to whether this line is blue or pink.

If you could have trouble telling the difference, the test probably isn't right for you.