Some 30 million people had taken an at-home DNA test as of early 2020. That number could be as high as 100 million in the following 24-month period if the MIT Technology Review’s predictions are right. Success stories like finding a birth parent or discovering that you’re related to a former president would make anyone consider adding a DNA test to their bucket list.

Though DNA kits have become increasingly popular gift items year after year, direct-to-consumer DNA testing is still a pretty new concept — one that people may not fully understand. Is it accurate? Is it safe? Apprehension about DNA test kits is sure to make some people hesitate — and that sucks, because finding out the who, what, and where that made you into the person you are is way too awesome to pass up.

Here’s what you need to know.

How does DNA testing work?

You know the drill: Request a kit, swipe the inside of your cheek with the provided cotton swab, send it back, and get your results in a few weeks. What type of results (or the level of detail in those results) depends on the type of testing your kit provides:

Autosomal testing is the most basic and most popular means of genetic testing, commonly known as the family finder. Autosomal DNA tests look at 22 pairs of chromosomes not involved in determining a person’s sex. It is used for cousin and distant relative matching as well as mixture percentages, or your ethnic mix (as shown in the percent pie charts from commercials), plus common genetic traits, like heritable diseases and hair type.

While autosomal testing shows who your relatives are, remember that this is a mix of both sides and doesn’t necessarily identify which side of the family they came from.

mtDNA testing uses mitochondrial DNA to trace your mother’s lineage. These are the DNA strands passed down from mother to child. There’s very little chance that these could be altered, so your direct maternal line can be traced back quite far.

Y-DNA testing focuses on the Y chromosome and traces your father’s lineage. These are the DNA strands passed down from father to son in the paternal line. It’s important to note that only males can use a Y-DNA test directly — but women can usually connect their DNA profile with a father, brother, or other male relative to get these results.

mtDNA and Y-DNA tests can trace back anywhere from 20-100 generations, while autosomal tests max out at five to eight previous generations.

Health screenings and trait analysis are the next iteration of DNA tests, jumping from just a few options (23andMe was the only reliable one for a while) to more popular kits offering some sort of look into genetic health risks and medical issues. These use your genetic markers to pinpoint potential illnesses or diseases you may be at risk of inheriting, as well as how your risks compare to other people of your age, race, and gender. Traits like hair and eye color, earlobe type, cilantro aversion, or male hair loss may also be a part of the test, providing insight into the physical and sensory genes that make you unique or genes that you’re likely to pass to your children.

It’s important to remember that while all of this data can be fun, in now way should it take the place of regular doctor visits and the kind of reliable testing that happens in a medical testing.

DNA testing pools get more robust by the year

If you tried an at-home DNA kit a few years ago and weren’t satisfied with the vague results, you may get better answers the second time around.

DNA companies are continuously expanding their pools so they have more data to compare: In 2019 alone, 23andMe added 1,000 new regions and 30 new Ancestry Detail reports. AncestryDNA updated its ethnicity estimates with new regions in Europe, the Americas, Oceania, and South Asia and a reference panel of over 40,000 samples.

These expansions lead to more granular reporting, like more precise differentiation between geographic neighbor areas that may have previously been lumped together.

Despite the growth, most at-home DNA tests are still widely euro-centric. The shortcomings when it comes to reference populations for people of color, results of polygenic risk score tests for non-European people, and employment diversity are slowly being addressed by companies like 23andMe, but there’s still no super reliable kit dedicated to typically non-white populations. (The AfricanAncestry kit is an option, but receives mixed reviews. More on that below.)

Which DNA test is the most accurate?

It’s hard to say which DNA test is the most accurate. Different DNA companies have different strengths and weaknesses, and discrepancies between results don’t automatically mean one test is skimping. One company may have a massive reference pool from hundreds of thousands of different regions — giving you a better chance of getting a well-rounded report of all possible ancestors — but that broadness could gloss over nitty-gritty details. A competing company may hone in on a specific region and be able to provide a wealth of detail about that region, but customers would need to have a previous inkling about their ancestry to choose such a specific test in the first place.

Do at-home DNA tests protect your privacy?

Some people can get freaked out by the idea of a profit-driven company having access to one of the most sensitive pieces of data that could exist about a person. It’s a valid concern — DNA companies potentially making money off of your personal information doesn’t sound great.

It’s crucial to remember that genetics data gathered by mail-in testing kits isn’t classified as official medical health data, which means it isn’t protected by HIPAA regulations. A company’s privacy protocol — what info it collects or keeps, how much control you have, and how to delete data — could be ambiguous (not necessarily ill-intentioned, but we digress), so tear that privacy policy apart before moving forward with a test. Many permissions operate via opt-in consent, so your returned cotton swab will be taken as a hard “Yes, this is fine.”

However, in 2018, Ancestry, 23andMe, MyHeritage, and others pledged to obtain separate “express consent” before sharing your info with outsiders. 23andMe is open about its partnership with pharmaceutical mogul GlaxoSmithKline to streamline drug development and Ancestry was previously working with Google Calico to study human longevity. In most research studies, any identifying information like names or addresses are stripped.

Pet DNA tests: How to become even more obsessed with your fur baby

No, buying a DNA test for your pet is not extra. As our loyal companions, they deserve a better answer than “IDK, just a mix” when someone asks what breed they are.

Just like humans use DNA tests to piece together their family tree, get an ethnicity breakdown, or learn about medical predispositions, pet DNA tests offer information about your pet’s family history, breed mix, and risk of health issues. They’re an especially handy tool for parents of rescued fur babies and super-mixed mutts. (Just remember that these tests are not a replacement for vet visits, but could flag an issue to bring up to a vet.) Like the human cheek swab process, an at-home pet DNA test is as easy as swabbing the inside of their cheek — if you can get them to cooperate, that is.

Which DNA test is best?

What — or who — are you looking for? The best DNA kit all depends on how you want to anatomize your lineage. Here are the best DNA test kits for every curious mind: