If you are newly suspicious about the safety of products in your medicine cabinet, Valisure, a small laboratory in New Haven, Connecticut, is likely to thank or blame.

Hidden away in an ordinary office park, Valisure’s team of around a dozen scientists has in the past five years found potentially cancer-causing chemicals in widely used medications, hand sanitizers, antiperspirant body sprays, dry shampoos, and most recently acne treatments. When Valisure raises concern about a new frightening finding, a flood of headlines, lawsuits, and product recalls often follows. The company is helping to break an illusion that consumers assume products for sale must be proved safe.

“Most consumers assume that because it’s for sale, it must be safe,” says Teresa Murray, who directs the consumer watchdog office at the nonprofit U.S. Public Interest Research Group (PIRG). “Often, that’s very much not true.”

Despite its nearly $7 billion annual operating budget, the U.S. Food and Drug Administration (FDA) isn’t analyzing every shampoo or supplement on sale at your local drugstore. In fact, the FDA does not approve most cosmetics before reaching shelves—let alone assess how they’ll affect human health after years of regular use. This information gap has given rise to a network of nonprofits, consumer-protection groups, and independent scientists dedicated to informing the public about potential hazards lurking in their products.

Within this group, Valisure has been uniquely effective at grabbing attention. Its testing has led to product recalls from household brands and partnerships with big organizations and the Kaiser Permanente health system. But Valisure—the underdog that built its reputation as a crusader for public health—has also made enemies. Critics and regulators have denounced its testing methods and the legitimacy of its scientific findings, raising doubts about the very doubts the company has raised. So every time Valisure’s results make the news, Americans are left to figure out how worried they should be.

The idea for Valisure came not from a grand plan to overhaul decades-old regulatory structures, but from one friend venting to another.

In 2015, David Light, a molecular biologist, heard from his friend and former Yale University classmate Adam Clark-Joseph about a problem with his medication. Every so often, Clark-Joseph said, he got a batch that triggered side effects and sent his chronic condition into relapse. He said his doctors mostly shrugged off these incidents as unfortunate quirks of a health care system where quality assurance is difficult. Light remembers being far more shaken than his friend’s physicians.

“It was shocking to both of us to realize the FDA’s not testing everything, and retail stores and pharmacies aren’t doing the testing,” he says. “So who’s actually testing the product, as opposed to looking at the paperwork?”

Light and Clark-Joseph—now Valisure’s president and head of analytics, respectively—co-founded Valisure in 2015 to fulfill that mission, setting up shop down the road from their alma mater. At first, Valisure quality-tested medications, then sold them through its own online pharmacy. But four years after its founding, Valisure made a name for itself in a splashier way.

In September 2019, Valisure’s scientists used a citizen petition, which everyday people can use to request action from the FDA, to announce they’d found the probable carcinogen NDMA in every batch of the heartburn medication ranitidine that they tested. Then lawyers brought a slew of lawsuits against GSK and Sanofi, pharmaceutical companies that have sold the popular ranitidine drug Zantac, linking it to clients’ cancers. (Many of these cases have been settled or dismissed.) In April 2020, the FDA requested withdrawal of all ranitidine medications from the market.

The FDA has said that the recall was based on its own testing, not Valisure’s. Though FDA tests did find elevated NDMA levels—high enough to trigger a recall—they were much lower than Valisure’s. That’s because Valisure used extreme testing practices, like exposing the drugs to heat, that may have actually produced NDMA, the FDA said in response.

But to the public, a recall is a recall, and Valisure had been the first one to sound the alarm. The scandal boosted Valisure’s reputation; Light still keeps Zantac-branded memorabilia in his office as evidence of his lab’s impact.

In 2021, Valisure sold off the pharmacy business to focus on product testing. Mostly—thankfully—this business is a boring one. Valisure’s clients are mainly organizations, like health care systems, that buy lots of medications and want to know what’s in them. About 90% of the time, Light says, this testing is uneventful. But now and then, often operating on their own hunches, his staff finds something concerning. Over the past few years, Valisure has found the carcinogen benzene in a variety of consumer products, including sunscreen, dry shampoo, and acne treatments, leading to major news cycles and, in some cases, product recalls.

A range of other groups work in this space. Experts from the Cosmetic Ingredient Review assess the safety of ingredients used in beauty products, with funding from the Personal Care Products Council, an industry trade group. The University of Kentucky’s health care system also performs independent analysis of medications.

But unlike Valisure, many of the other groups informing the public about products with questionable safety data—including the Ralph Nader–aligned PIRG, the Silent Spring Institute, Toxic-Free Future, and the Environmental Working Group (EWG)—are nonprofits. Sunscreen is a concern—not necessarily because of benzene contamination, but because of chemical ingredients linked to hormone disruption and cancer—as are things like hair products (some containing formaldehyde) and fragrances. These groups have made splashes too; PIRG was behind the campaign to ban toxic chemicals in baby products, leading to recalls.

“The more we look [at consumer products], the worse it looks,” says Dr. Megan Schwarzman, associate director of the Center for Green Chemistry at the University of California, Berkeley. But, Schwarzman says, it’s not always easy for scientists, let alone the average consumer, to understand what to make of the potential risks raised by these groups. “There’s lead in pigments in lipstick,” Schwarzman says. “If you wear lipstick once a month, it’s probably not a big exposure”—but is wearing lipstick a few times a week enough to cause health problems over years or decades? Is the risk high enough to swear off lipstick altogether? What about other cosmetics? These questions are difficult even for scientists to answer.

It’s also near impossible to isolate causation, because “we are exposed to [toxins] at generally very low concentrations all the time,” adds Debra Kaden, a toxicologist and principal consultant at the environmental-consulting firm Ramboll. An astounding number of the products in the average American home, for example, contain synthetic chemicals linked to health issues.

Given those realities, consumer-protection groups have their work cut out for them—which is an indictment of the U.S. regulatory system, says Homer Swei, who oversees consumer-safety science at EWG. “It would be great if there was no need for organizations like this,” Swei says. “Why does a third party have to do the heavy lifting for industry and government?”

The FDA regulates most things that Americans put on and in their bodies, from vaccines to tobacco products, but the scope of its oversight varies depending on the product. Pharmaceutical companies have to conduct complex clinical trials and secure FDA approval before bringing new drugs to market. Meanwhile, the agency’s regulatory structure for cosmetics stems from a law enacted in 1938.