DNA services are testing products that analyze your genetic material to provide information about your health, ancestry, family relationships, or how your body responds to medications and nutrients. These services range from at-home saliva kits you order online to clinical tests ordered by a doctor, and they vary widely in what they measure, how regulated they are, and what you can do with the results.
Clinical vs. Direct-to-Consumer Testing
DNA services fall into two broad categories. Clinical genetic testing is ordered through a healthcare provider, such as a physician or genetic counselor, who determines which test is needed, sends your sample to a lab, and interprets the results with you. Health insurance often covers part or all of the cost.
Direct-to-consumer (DTC) testing works differently. These are the kits marketed online or in stores by companies like 23andMe and AncestryDNA. You order the kit yourself, provide a saliva sample at home, and receive results through an online portal. No doctor visit is required, though the depth and clinical usefulness of results varies significantly depending on the product.
Ancestry and Ethnicity Estimates
Ancestry testing is one of the most popular DNA services. These tests compare your DNA against reference panels of people with well-documented origins from specific world regions. The algorithm estimates what percentage of your genetic makeup traces back to each region. For most samples in a given reference group, companies like AncestryDNA predict at least 80% of the genetic ethnicity from the correct region, and some populations (such as Finnish/Northwest Russian ancestry) are estimated with close to 100% accuracy.
These estimates improve over time as companies expand their reference panels. But they remain estimates. Two siblings can receive slightly different ethnicity breakdowns because of how DNA is randomly inherited from each parent. Ancestry services also connect you with genetic relatives by matching shared DNA segments across their customer databases, which is how many people discover previously unknown cousins or half-siblings.
Health Risk Screening
Some DNA services test for genetic variants linked to an elevated risk of developing certain diseases. The FDA has granted marketing authorization to tests that screen for variants in genes like BRCA1 and BRCA2 (associated with hereditary breast and ovarian cancer), Lynch syndrome genes tied to colorectal and other cancers, and genes associated with hereditary gastric cancer.
One authorized test evaluates 47 genes known to be associated with elevated cancer risk, identifying hundreds of specific variants across those genes. It’s important to understand what these results mean in practice: a positive result indicates higher risk, not a diagnosis. And a negative result doesn’t guarantee you won’t develop the condition, because these tests screen for known variants rather than sequencing every possible mutation. Clinical-grade health screening typically requires a blood sample collected in a doctor’s office, while DTC health reports use saliva and cover a narrower set of variants.
Pharmacogenomic Testing
Pharmacogenomic DNA services analyze how your genes affect your body’s response to medications. Certain genetic variations change how quickly or slowly you metabolize specific drugs, which can influence whether a medication works well for you or causes side effects. Your doctor may order a pharmacogenomics panel that tests multiple genes at once, typically from a blood sample. The results help your healthcare team choose medications and dosages more likely to be effective for you personally, particularly for drug categories like antidepressants, blood thinners, and pain medications where genetic variation has a well-established impact on outcomes.
Diet and Fitness Reports
A growing segment of DNA services offers personalized nutrition and fitness recommendations based on your genetic profile. These tests look at variants in genes related to caffeine metabolism, vitamin absorption, iron regulation, vitamin D processing, and body composition traits like how you respond to different ratios of fat and protein.
The science behind these services is uneven. The strongest evidence exists for caffeine: variants in the CYP1A2 gene reliably predict how quickly you metabolize caffeine and how it affects endurance performance. Evidence also supports genetic influences on folate, vitamin B12, and vitamin D needs. However, researchers caution that there is a lack of evidence for using genetic profiles to prescribe specific exercise programs or identify athletic talent. Your genetic profile is one useful data point, but it works best alongside other factors like age, sex, health status, family history, and dietary preferences rather than as a standalone guide.
Paternity and Relationship Testing
DNA paternity and relationship services confirm biological connections between individuals. These tests come in two forms: at-home kits for personal knowledge and legal tests that produce court-admissible results. Both types routinely achieve accuracy of 99.99% or higher for positive results.
The key difference is chain of custody. Legal tests require sample collection at a certified facility where staff verify each participant’s identity and document the handling of every sample from collection to analysis. This documented chain of custody is what makes the results usable in court for child support disputes, custody cases, and probate matters. At-home kits use the same underlying science but lack this documentation, so while they give you reliable answers, those answers won’t hold up in legal proceedings.
How Labs Are Regulated
Laboratories that process DNA samples for health-related purposes in the United States must comply with federal certification standards known as CLIA (Clinical Laboratory Improvement Amendments). Most molecular genetic tests are classified as moderate or high complexity, which means the lab must hold either a Certificate of Compliance from the federal government or a Certificate of Accreditation from an approved organization. New York and Washington have their own state-level requirements that meet or exceed federal standards. New York, for example, requires on-site inspections, proficiency testing, and departmental review of any tests not already approved by the FDA.
DTC ancestry and wellness tests operate in a lighter regulatory environment than clinical health tests. This is one reason health-related genetic results from a DTC kit are generally not treated as equivalent to results from a clinical lab ordered by your doctor.
Privacy and Law Enforcement Access
When you submit DNA to any service, you’re handing over the most permanent identifier you have. How that data is stored and shared varies by company, and the protections are thinner than many people assume.
A review of 22 DTC companies found that all of them informed consumers about the possibility of law enforcement access or disclosure if required by law, but only 4 out of 22 explained how law enforcement should request that access. The major companies, Ancestry and 23andMe, have stated they resist law enforcement requests, though they acknowledge they may be compelled to comply with a valid legal order. FamilyTreeDNA takes a different approach: it uses an opt-out policy, meaning your profile is available for law enforcement matching by default unless you go into your privacy settings and turn it off. Over 96% of its U.S. users remain opted in.
The practical reality is that DTC companies’ terms of service and privacy policies, along with whatever self-imposed restrictions law enforcement agencies follow, are currently the only barriers to forensic access in the United States. There is no comprehensive federal law governing police use of consumer DNA databases.
Legal Protections Against Genetic Discrimination
The Genetic Information Nondiscrimination Act (GINA), passed in 2008, prohibits health insurers from using your genetic information to determine eligibility, set premiums, or make coverage decisions. It also prevents employers from using genetic information in hiring, firing, promotions, pay, or job assignments.
GINA has significant gaps, though. It does not cover life insurance, long-term care insurance, or disability insurance. If a genetic test reveals you carry a variant associated with a serious condition, a life insurer or long-term care provider could, in most states, use that information against you. Some states have passed their own laws extending protections to these insurance categories, but coverage is inconsistent. This is worth considering before taking any genetic test, particularly health-focused ones that screen for disease risk.