When Atlanta-based editor Lauren Finney got her weighted blanket, it was initially on the recommendation of a physical therapist to help with her joint compression. Now, she tells Mental Floss, she can’t sleep without it. Chicago-based software developer Brandon Behr echoes that sentiment, telling Mental Floss that his weighted blanket “helps tremendously when the anxiety brain won't shut down long enough to fall asleep.”

Weighted blankets (also called gravity blankets), filled with pellets or another material to make them weigh about 10 pounds or more, are all over social media and ads, drawing buyers in with promises of complete comfort and a better night’s sleep. Most brands recommend getting one that’s 10 percent of your body weight for optimal relaxation and comfort.

“The concept is that the sensation may send messages to the brain that increases a sense of well-being,” Dr. Susan Lipkins, CEO of Real Psychology, tells Mental Floss. “Some research suggests that it is similar to pressure massages, which have been shown to help the brain calm down.”

Alternately, says Dr. Kristin Addison-Brown, owner of NEA Neuropsychology, it could have to do with a feeling of being swaddled—an evolutionary throwback to childhood when we felt more safe and secure from the feeling of being tightly wrapped. Ultimately, the purpose of weighted blankets is to bring down a person’s base-level anxiety so they can get some rest, Addison-Brown tells Mental Floss.

Light Evidence on Weighted Blankets

Weighted blankets have been touted by their manufacturers as a calming agent for people with anxiety and autism—but Lipkins and Addison-Brown both point out that no substantive peer-reviewed research has been done on them.

“Right now, the empirical evidence is pretty weak,” Addison-Brown says. “I did see one randomized controlled trial where [children with autism] used a weighted blanket versus a regular blanket, but that trial didn’t [show] any objective differences” [PDF].

Interestingly enough, Addison-Brown points out, even though the two groups saw the same results scientifically, the parents and children involved in the study all preferred to use the weighted blanket over a regular blanket. The findings appeared in the journal Archives of Disease in Childhood in 2013.

“There’s something inherently pleasing to us about [gravity blankets], but we don’t exactly know why and any real objective measures are not reflecting back,” she says.

Are weighted blankets worth it?

It’s not a one-blanket-fits-all solution. Some people may actively dislike them, and the blankets can cause problems for others. It takes some trial and error to see if they’re the right option.

“Gravity blankets seem to help some people some of the time,” Lipkins says. “The weight, for some, creates a secure and safe environment, allowing the person to relax and fall asleep more easily. Others may feel suffocated and like they can’t move.”

The most common complaints that weighted blanket users told Mental Floss match that idea. Canadian journalist Johanna Read didn’t like the way her blanket pushed her feet into a point. Illinois-based former car technician Noah Dionesotes says he couldn’t get comfortable because he likes to sleep with one leg out of the blanket. Wichita, Kansas, resident Jocelyn Russell says the blanket she bought is too heavy and, ironically, it gives her panic attacks.

In fact, weighted blankets have the potential to be dangerous: The deaths of two children, a 7-month-old and a 9-year-old, have been linked to them.

Neither Lipkins nor Addison-Brown are anxious to prescribe the blankets as a solution, especially since their safety hasn’t been fully established. Instead, they suggest first trying other, more natural ways to fall asleep: don’t watch television late at night, turn off your screens, set a regular bedtime and waking time, and avoid caffeine.

“[You could] also consult a psychologist to help find out what is keeping you awake and how to reduce stress and anxiety in healthful ways,” Lipkins adds.

All that being said, go ahead and try gravity blankets—as long as you do so safely.

“If you can afford it, I don’t see any real harm in it,” Addison-Brown says. “Though I would be very careful using it with people who may have any kind of muscle weakness. You also wouldn’t want to have a child or baby in the bed with you. Just use caution and common sense.”