The Food and Drug Administration just granted the genetic testing company

23andMe approval to tell people whether they are at a higher risk for certain diseases — after ordering the company to stop doing precisely that in 2013. That’s a big turnaround for the Silicon Valley startup, but it’s not yet clear how helpful these tests will be for people’s health.

Like other California-based biotechs (such as Theranos), 23andMe had charged ahead with promises to disrupt health care. Company co-founder Anne Wojcicki said 23andMe was poised to become the "world's trusted source of personal genetic information" and was "empowering" users with information about their genetic makeup.

But that revolutionary language didn't pass muster with health regulators. Many of the genetic analyses 23andMe was giving to consumers hadn't yet been validated or FDA-approved, so the company's health service had to slow down and reboot for a couple of years until coming back online in 2015.

With today’s clearance from the FDA, 23andMe will become the first company to sell regulator-approved genetic predisposition tests directly to consumers. This is both a good and bad thing for consumers. It means people now have direct access to risk assessment information that’s actually backed by science, should they want to purchase it. But the results of these tests can be pretty difficult to interpret and even misleading.

23andMe can tell users if they’re at a higher risk for everything from Parkinson’s to celiac disease

According to the FDA, the 10 tests 23andMe can now run include:

The company said the tests won’t be available immediately, and it’s important to note that this is a big scale-back from the days before the FDA intervened in 2013. Back then, the company had offered its million-plus users risk assessments on 254 diseases and conditions based on an analysis of their DNA through a saliva sample.

The FDA and other critics said the science hadn't yet caught up to the company's interpretations of these tests. A person's risk of developing a particular disease can be determined by environmental and lifestyle factors as much as by genetics. Science is only just in its infancy when it comes to understanding how all these factors come together and influence human health.

So the FDA had serious concerns about the accuracy of the genetic interpretations 23andMe was giving consumers. In 2013, it sent a sternly worded letter to the company, ordering it to stop marketing health interpretations for its genetic testing service. (23andMe continued to offer its ancestry services, which were not a source of regulatory controversy.)

That letter was quickly followed by a class-action suit from people who alleged that 23andMe misled them by continuing to promote health promises without regulatory approval or good science behind them. The complaint notice also cited FDA concerns about potentially inaccurate and incomplete health risk assessments, which could lead people to make harmful choices.

But the FDA warns these tests are not the final word

After that, 23andMe went back into negotiations with the FDA, seeking approval for its health data. Today’s FDA clearance means they’ve been working hard to validate their technology.

“Authorization of the 23andMe GHR tests was supported by data from peer-reviewed, scientific literature that demonstrated a link between specific genetic variants and each of the 10 health conditions,” the FDA said in a statement. The FDA also said, through this approval, they’ve set up a regulatory pathway to get other direct-to-consumer risk assessments approved more efficiently — but they offered scant detail on what that pathway will look like.

Still, consumers shouldn’t take the tests’ results too seriously. “[It’s] is important that people understand that genetic risk is just one piece of the bigger puzzle, it does not mean they will or won’t ultimately develop a disease,” said Jeffrey Shuren, director of the FDA’s Center for Devices and Radiological Health, in the agency’s statement.

The tests only deliver genetic risk information, but they can’t take into account all the other factors that come into play in determining whether a person will get sick with a particular disease. So even if consumers find they’re at a high risk for a disease like celiac or Alzheimer’s, that doesn’t necessarily mean they’ll get it. And if they’re at a low risk, they may eventually come down with the illness later.

For this reason, consumers should be aware of false positive findings, the FDA warned, and shouldn’t view the test results as diagnoses. This will leave a lot of room for interpretation and confusion, as Stanford ethicist Hank Greely pointed out.

What surveyed consumers say they know may or not be quite diff from what they do. Expect primary care docs to get LOTs of Qs. Hope GCs used — Hank Greely (@HankGreelyLSJU) April 6, 2017

Over the phone, Greely said he doesn’t think these tests will harm consumers. But he’s just not sure what benefit they deliver. “I don’t think there’s very much consumers can do with [the information they get from these tests],” Greely said.

A systematic review of the research on the impact of giving people genetic risk information in the hopes of changing their health behaviors concluded there’s no evidence it works.

In other words, people don’t suddenly quit smoking, lose weight, or do all the other things they know they should be doing for their health when they find out they are at a higher risk of a certain disease.

There is one place Greely thinks this approval will have an impact: sending a signal to other startups rushing to market ahead of medical regulation. “Silicon Valley is almost allergic to FDA and regulation. But it looks like working with the FDA is a lot better than ignoring it.”