Do you get better sleep with a weighted blanket? Here are the key facts

There are certain inventions which change our lives and make them easier, for the better – and they make it to the «TIME’s Best Inventions» list of the year. In 2018, the time had come for the company Gravity and its weighted blanket. It was featured in the US magazine alongside wind turbines for private rooftops, unbreakable tights, rapid malaria tests using a light sensor instead of a blood draw, and 46 other things in the showcase of ingenious new products.

The blankets, which weigh up to 12 kg, are said by the manufacturer to lead to better, deeper sleep. The gentle pressure, which resembles a hug, calms the nervous system and promotes the release of the sleep hormone melatonin.

In addition to the advertising, the product’s success story also played a role in its nomination for the list. Within just a few months, the start-up company raised almost 5 million US dollars via the financing platform Kickstarter and sold 18 million blankets after its market launch at a unit price of around 250 dollars. It’s a success which company co-founder, Mike Grillo, attributed to its handsome design – but also to Donald Trump’s presidency, when many Americans were looking for ways to manage their anxiety and sleep disorders.

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However, the award wasn’t entirely fair. Gravity may have marketed its blankets perfectly and thus hit the zeitgeist of the insomniacs, but the company didn’t invent weighted blankets. They’ve been used for years as sensory therapy blankets, for example for autistic children, for patients with Tourette’s, dementia, Alzheimer’s and Parkinson’s, and for soldiers suffering from PTSD.

As early as the late 1990s, American physician Tina Champagne had researched its efficacy for mentally ill people and summarised her study results in a conference paper in 2007. Anxiety symptoms in particular could be reduced with the help of such blankets. According to one of her observations, her test subjects were able to calm themselves down again during panic attacks, for example.

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As a rule, the weight of the blanket should be about ten per cent of your body weight. Placed over your body while sitting or lying down, it exerts a gentle, even and static pressure. This results in the calming effect. For this deep pressure stimulation or «deep (touch) pressure stimulation», plastic beads or tiny glass beads are usually sewn into the numerous blanket layers and inserts.

The term «deep touch pressure» was coined in the 1960s by Temple Grandin. The US native, who became known as the «cow whisperer», struggled with anxiety for a long time as an autistic woman. At some point, while observing her herd of cattle, she discovered that agitated animals – for example, during a visit to the vet – relaxed when they were tightly constricted to the side of the hall when waiting. She then designed a device to apply pressure to her own body using padded plates. The result: after a few minutes, her fears subsided significantly.

She was able to demonstrate the calming effects of pressure stimulation in studies with autistic children and healthy college students too.

Parents have been taking advantage of this effect for centuries if not millennia, by the way, by wrapping their baby tightly in a blanket. This swaddling technique has a calming effect on offspring, but it’s controversial as it can lead to overheating and hip misalignment.

The «side effect» of good sleep

It’s not just anxiety disorders that weighted blankets may help with. In Stockholm alone, 2,700 such blankets are prescribed each year to adults undergoing psychiatric treatment for depression, for example, and who are suffering from insomnia, falling asleep and middle-of-the-night insomnia. «They lead to significantly better continuous sleep,» says Dr Mats Adler, a specialist in psychiatry and general medicine.

According to a study he conducted which was published in 2020 in the Journal of Clinical Sleep Medicine, about 60 per cent of patients were shown to benefit from intervention with the weighted blanket. They reported higher activity levels during the day and fewer symptoms of fatigue during the day – as a result of a significant improvement in their sleep quality due to the weighted blankets.

So it’s not labelling fraud when manufacturers like Gravity advertise a sleep-improving effect with their weighted blankets. However, it hasn’t been clearly proven if the results can also be transferred to people who don’t suffer from mental disorders or psychiatric illnesses.

Effects on the hormonal system?

For example, the question of whether the blankets actually influence the body’s hormonal system as the manufacturers claim, remains unanswered. The deep pressure is supposed to send the same signal to the brain as a loving embrace does by promoting the release of melatonin, also known as the sleep hormone. This lowers cortisol levels and thus stress levels. While such biological changes have been proven for relaxation massages, for example, there are no studies showing that similar things happen in the body when weighted blankets are used.

Psychologist Stephanie Margarete Müller, head of a junior research group at the Haptics Research Laboratory of the University of Leipzig, therefore emphasised to the specialist journal «Spektrum der Wissenschaft» (Engl.: spectrum of science; page in German) that the findings on the effects of massages can’t simply be transferred to weighted blankets. After all, during a massage the body is moved and shifted very dynamically and there’s interpersonal contact.

No general recommendation

The authors of a review paper, who examined eight studies published to date – three of them on sleep disorders – came to a clear conclusion: no general recommendations could be derived for weighted blanket use for a better night’s rest. On the one hand, sleep disorders can have many causes other than mental suffering, including physical illnesses – which the blankets are of little help for. On the other hand, there are people for whom the weight of the blanket causes trepidation, sometimes even pain.

Also, for people who sweat more at night or move a lot, the blanket isn’t very suitable. Perhaps it only helps them fall asleep. It can be difficult to turn under the heavy blanket, which would reduce rather than improve the quality of sleep. Anyone who suffers from respiratory or circulatory problems shouldn’t use them, or should only use them after consulting a doctor. The blankets are generally not suitable for children under five years.

What to look for when buying a weighted blanket

Nevertheless, experts don’t generally oppose weighted blankets for sleep problems. Women who often feel cold, anxious people who have difficulty falling asleep and anyone who lies very still are especially likely find the blankets helpful and soothing. The psychologist Stephanie Müller, who has also collected facts about weighted blankets in a haptics textbook for health professions (book in German), advises us to give it a try. «You usually know within a few minutes whether you find the pressure comfortable and relaxing.»

If the blanket has passed the first relaxation test in store – relaxation being the basic prerequisite for sleep – this is a good starting condition. What else should you consider before buying, so that you don’t regret the investment of up to several hundred francs or euros?

Depending on the manufacturer, the blankets weigh between 4 kg and 12 kg. The weight of the chosen model should be about one tenth of your own body weight. It’s best to go for a weighted blanket with standard dimensions so you can cover it with ordinary bed linen.