Are you second-guessing your decision to participate in DNA testing? Depending on which testing kit you used, deleting your results from the company’s database may be trickier than you think.

23andMe

Deleting your entire account and all personal information is easy enough. Just go into your account settings and deactivate the account.

As for the DNA sample you sent, 23andMe offers the option of storing, or biobanking, samples. Samples are destroyed after analysis unless you give consent to store them.

If you’ve changed your mind about giving consent, make the change in account settings immediately after sample processing is complete.

You may also have granted permission for your data to be used in research; 23andMe partners with a pharmaceutical company that uses genetic data to develop new drugs. A separate agreement allows the company to share data with other external researchers, but the identifying information is removed first.

For either of these scenarios, go to the account settings page to revoke consent.

Note that it’s impossible to delete data that was used in studies that have concluded. That goes for genetic data that is currently being used as well, but your data won’t be used in future projects if you withdraw consent.

However, 23andMe has a legal obligation to retain the genetic information, sex information, name, and date of birth associated with samples that were used for research in its certified third-party labs. Certified labs, in compliance with the Clinical Laboratory Improvement Amendments, must hang on to that information for at least 10 years.

Ancestry

To delete your data at ancestry.com, simply delete your overall account. If that sounds too simple, log in online. Select the DNA tab. Click on the results summary. Go into settings, and click on the tab labeled “Delete Test Results.”

Ancestry promises to “delete all Genetic Information, including any derivative Genetic Information (ethnicity estimates, genetic relative matches, etc.) from our production, development, analytics, and research systems within 30 days.”

If you want to keep your account and genetic information but have your sample destroyed, make a request through the member services department.

If you’re unsure whether you gave permission for your data to be used in research, check your status on the settings page. There, you may opt out if you prefer.

Like 23andMe, Ancestry can’t wipe out data that is being or has been used in research. Its labs don’t presently require it to keep customer data, but regulations could change in the future.

Family Tree DNA

There’s no do-it-yourself option for deleting your data or having your sample tossed out at Family Tree. You may only take these actions by contacting customer service.

As is common, you can’t delete genetic information that has already been shared with others or used in research.

Family Tree is happy to remove your name from its matches list, but be aware that you won’t be able to see matches either. You can reverse the withdrawal at any time if you decide to access your results in the future.

If you want the data permanently removed, you’ll have to sign something confirming that you understand removal is permanent. In other words, the information cannot be reinstated, and you’ll have to start over with a new kit if you change your mind.

Whether to have your DNA sample stored or destroyed is up to you.

Other Brands

With MyHeritage, you can delete your data under the “Manage DNA Kits” tab. Alternatively, you can contact customer support. To withdraw permission to use your data in internal research, go to your account settings page. Click on “Privacy” followed by “My DNA Preferences.” You can’t remove data that has already been used for research or is being used in a current study. For now, MyHeritage doesn’t share genetic information with third-party research labs.

Since 2005, close to a million people have participated in the Genographic Project coordinated by the National Geographic Society. The goal of the project, which runs through 2020, is to discover and understand patterns of human migration.

Geno 2.0 Next Gen Helix Product is the testing kit used. In the project’s privacy policy, the society is careful to emphasize that requests to destroy data apply only to the information it holds. You must also contact Helix and make a separate request to have shared information destroyed.

Living DNA has a mere blurb on its website about deletion of data or questions about how it’s used. It directs users to contact the help desk.

The Vitagene promise reads, “You can delete your data at any time. This will remove your information from all of our servers.” Vitagene doesn’t sell or license genetic data to third parties, and users retain ownership of their DNA samples. As with Living DNA, you can make changes only by contacting customer support.

For Those Considering Genetic Testing

The companies discussed here are fairly transparent about how they use clients’ DNA samples and results, but that’s not the case with all brands.

Dr. James Hazel, a postdoctoral fellow at Vanderbilt University Medical Center, has done extensive research and published his findings on the privacy policies of DNA testing companies. Of the 90 companies he investigated, 40% had no posted policy about how they use clients’ information.

Many people upload their genetic data on external sites in order to broaden their search for relatives or glean more insight about their health risks. That leaves data even more susceptible to misuse. Users should scrutinize the sites’ policies to make an informed decision.

The U.S. Federal Trade Commission strongly advises consumers to compare privacy policies, take care when choosing account settings, and report concerns about misuse to the authorities.