A “Gravity blanket” on Kickstarter that claimed to use cozy pressure to treat anxiety, post-traumatic stress disorder, and other conditions has been taking the internet by storm, raising more than $3 million. But on Thursday, the company quietly deleted the boldest medical claims on its crowdfunding site — language which violated Kickstarter policy and went against FDA recommendations — after STAT inquired about about its promotional statements.

The creators of Gravity call their product a “premium-grade, therapeutic weighted blanket” intended to treat psychiatric illnesses. People quickly snuggled up to the idea: More than 15,000 donors contributed to the Kickstarter campaign to help get the blanket to the market, where it’s projected to sell for as much as $279.

A slew of publications have touted the product with headlines such as, “I Want This Anti-Anxiety Blanket and You Will Too.” But the science behind the blanket’s claims is scarce— as STAT found by reviewing the studies the manufacturer cites as evidence for its claims.

The Kickstarter campaign made big promises: “The science behind Gravity reveals that it can be used to treat a variety of ailments, including insomnia, post-traumatic stress disorder, obsessive-compulsive disorder, attention deficit hyperactivity disorder, as well as circumstantial stress and prolonged anxiety.”

But on Thursday afternoon, that language was swapped to say the blanket could be “used” for those conditions, rather than treat them. The blanket’s creators didn’t respond to a request for comment. After STAT inquired about the campaign with both Kickstarter and the Gravity blanket’s creators, Kickstarter said it asked the Gravity team to change the language because it wasn’t in line with their rules on health claims.

Gravity isn’t the type of product regulated by the Food and Drug Administration. However, FDA recommendations released in July 2016 laid out clear guidelines for promoting wellness products, which are low-risk items designed to support a healthy lifestyle.

They can be marketed as supporting people who live with anxiety. They shouldn’t claim that a product can treat an anxiety disorder.

The marketing language also appeared to violate Kickstarter’s rules. The crowdfunding site prohibits campaigns for “any item claiming to cure, treat, or prevent an illness or condition.” Kickstarter has previously said that the rule was developed out of concern that medical claims could have “harmful consequences” for consumers.

Regardless of how it’s promoted, the evidence behind the product is scarce.

“It’s not a miracle therapy,” said Dr. Khalid Ismail, a sleep medicine researcher at Tufts Medical Center in Boston. “I don’t think it’s ready for prime time yet.”

Weighted blankets simulate the feeling of a big hug. The creators say it’s similar to swaddling a newborn baby, but with a much higher price tag. They claim that the increased weight — also known as deep touch pressure stimulation — can increase serotonin and melatonin levels while driving down cortisol, a stress hormone, “all without filling a prescription.”

It’s not a novel concept: Weighted blankets have been used in children with autism and elderly individuals with dementia. You can even buy them with a lower price tag from home goods stores.

“What’s new is that they’re trying to broaden the indication for its use,” said Ismail.

But the research they cite falls short of the hype.

One study looked at the use of weighted blankets, among other products, in a “sensory room” in an inpatient psychiatric unit. The researchers studied 75 people who used that room and concluded that those who tried the blanket reported a decrease in their anxiety and distress. But there was also a decrease in those symptoms among people who didn’t get under the blanket. And the study wasn’t blinded, so people might’ve reported positive effects because they were led to expect the blanket would have a positive effect.

Another study touted by Gravity’s creators found that 63 percent of individuals who used a 30-pound weighted blanket had reduced symptoms of anxiety. But the research included only 32 adults and no control group.

The creators of the blanket did not respond to a request for comment.

Ismail said it isn’t clear who, exactly, the blanket would benefit. Many cases of sleeplessness result from poor sleep hygiene, like being glued to a phone before bed; others result from underlying psychiatric disorders that require treatment.

“It might have a role, but in a very, very small subset of patients,” Ismail said, “and I don’t think we’ve identified that subset of patients with a really good randomized controlled trial.”

The campaign says it expects to start shipping blankets this month.

Republished with permission from STAT. This article originally appeared on May 12, 2017