How Accurate Are At-Home DNA Test Kits? What You Need To Know Before You Use One

At-home DNA test kits have exploded in popularity. And it’s easy to see why.

With a simple saliva sample and a few clicks online, you can learn about your ancestry — and some claim, your risk for certain health conditions.

That easy access can feel empowering, especially if you’re curious about your health and your family’s background. But these tests can also raise important questions: Are they reliable? And when you get results, what do you actually do about them?

Certified genetic counselor Marissa Coleridge, CGC, says these tests can be useful, but only when you understand their limits. Here’s what to know before you put your sample in the mail.

What are at-home DNA tests?

At-home DNA test kits are designed to give you some genetic information, without having to step foot into a doctor’s office.

Coleridge calls them “direct-to-consumer” tests, and there’s a wide range of them.

• Ancestry tests can give you an idea of where your ancestors came from and whether you’re a DNA match to others in the company’s database.
• Traits tests can provide interesting information about your body, like whether you make more earwax than other people or if you’re genetically predisposed to being a night owl.
• Genetic carrier tests analyze certain genes and suggest whether you’re likely to pass on certain health conditions to your child.
• Health risk tests attempt to assess your personal risk for developing conditions like cancer, Alzheimer’s disease and more.

While that information can be interesting — and helpful at times — it may not tell the whole story.

“I think of direct-to-consumer DNA tests more as an educational tool or an opportunity to start a conversation,” Coleridge recommends. “They really shouldn’t be the final word, especially when it comes to your health.”

How they work

Most at-home DNA tests follow a similar process:

• You buy a kit online or at a store.
• You collect a sample at home, typically by swabbing your cheek or spitting into a tube.
• You send your sample to a lab for analysis.
• Your results are sent back to you, typically within a few weeks.

The process of collecting your DNA couldn’t be simpler. But the analysis isn’t so straightforward. And that’s where things get tricky.

How accurate are they?

Some at-home DNA tests are more accurate and trustworthy than others.

If you’re curious about things like whether you’re a “supertaster,” that’s pretty safe. The same goes for tests that give you a better understanding of your family tree (assuming you’re prepared for the possibility of unlocking some secrets).

But home tests for more consequential health matters, like your risk for breast cancer or whether you’re a carrier for genetic diseases, can put you on shakier ground.

“Direct-to-consumer testing can be fun for things like ancestry or certain traits,” Coleridge acknowledges. “But for any health-related information, you really need to slow down and be cautious.”

At-home DNA test results can miss important details or flag harmless genetic differences as serious concerns. In one study, about 40% of genetic variants reported in direct-to-consumer data turned out to be false positives when reviewed by clinical laboratories.

The opposite can be true as well, Coleridge notes. Some at-home DNA tests can reassure you that all is well when, in fact, there may be reason for concern.

Coleridge shares a few reasons why that happens:

• Partial genetic testing: Many at-home tests look at a few specific “hot spots” — not your entire genome. But many health conditions are influenced by more than one gene. That means results may misinterpret important information.
• Gray areas: Not all genetic results have a clear meaning. Clinicians are trained to interpret these nuances. But at-home tests are prone to presenting them as definitive results — turning uncertainty into answers that seem more conclusive than they actually are.
• Interpretation varies widely between companies: Different testing companies and labs may classify the same genetic finding differently, leading to confusion or conflicting results.
• Lack of medical context: Unlike clinical genetic testing with a provider, at-home kits aren’t likely to factor in your personal medical history, family history or environmental risks — all of which matter when understanding what a genetic result may mean for your health.

When it comes to your health, Coleridge warns against using DNA self-testing as a replacement for professional medical guidance.

But if you do take the DIY approach, proceed thoughtfully.

One way to reduce the risk of inaccurate results is to check whether the testing is done in a quality lab. Look for tests that are completed in a CLIA-certified laboratory. These labs are regulated by the Centers for Medicare & Medicaid Services (U.S.) to confirm they meet federal standards for testing quality, procedures and staff qualifications.

“There are so many labs out there offering direct-to-consumer testing,” Coleridge says. “Knowing whether testing is performed in a certified lab can increase your confidence in them.”

Even then, again, it’s important not to just take your results at face value.

“Self-test kits can be a good way to start a conversation with a doctor or a genetic counselor,” she continues. “They can give you reason to bring up things you wouldn’t have otherwise considered.”

It’s important to consider your health privacy as well. At-home DNA testing companies aren’t always subject to the same laws that protect your medical information as hospitals and other medical facilities. That means, in some cases, your information may be shared with third parties, including law enforcement, insurance companies and others.

Final thoughts: Test results aren’t a guarantee

At-home DNA test kits are convenient, affordable and can satisfy your curiosity. But they work best as a starting point — not a stand-alone answer.

Remember, too, that DNA tests are tools to help you understand your risk. They’re not crystal balls.

“Genetic testing is just one piece of the puzzle,” Coleridge reiterates. “Many common conditions are influenced by multiple genes, as well as lifestyle and environmental factors.”

If you’re considering genetic testing or have already received results, talking with a doctor or genetic counselor can help you understand what the information actually means for you. With professional guidance, you can put those results into context and make thoughtful decisions about your health.