Weighted blankets: the main trial, and who was in it
Most weighted blanket marketing leans on one Swedish trial. Its headline numbers are striking. Who took part, and how sleep was measured, matter just as much.
contentsThe trial behind the claims
Key points
- The main trial studied 120 adults with insomnia alongside depression, bipolar disorder, anxiety or ADHD.
- After 4 weeks, 59.4% on an 8 kg chain blanket had their insomnia score halved, versus 5.4% on a light blanket.
- Wrist sensors showed no significant change in measured sleep.
- The results may not apply to people without those conditions.
- One person left the study because the blanket made them more anxious.
The trial behind the claims
In 2020, researchers in Stockholm randomly gave 120 adults either a heavy metal chain blanket of about 8 kg, with a 6 kg option, or a plastic chain blanket of the same size weighing about 1.5 kg. Everyone had long-standing insomnia and a psychiatric diagnosis. They used the blankets for four weeks.[60]
The headline numbers
chart · after 4 weeks
Far more people improved on the heavy blanket
Response, light blanket
5.4%Response, heavy blanket
59.4%Remission, light blanket
3.6%Remission, heavy blanket
42.2%
Those are large differences for a sleep study. After the four weeks, everyone could choose a heavy blanket and was followed for a year, with good results reported, but that later phase had no comparison group.[60]
What the wrist sensors said
Participants also wore wrist sensors. Those showed no significant change in measured sleep, even though people reported sleeping better, especially staying asleep.[60]
That does not cancel the result. How sleep feels matters, and insomnia is defined partly by how people experience their nights. It does mean the blanket may be changing comfort and perception more than the clock.
Who was in it
Every participant had insomnia together with major depression, bipolar disorder, generalized anxiety or ADHD, and most were on medication.[60] It is not obvious that the same results would appear in people with ordinary stress and no psychiatric diagnosis. That trial has not been done at the same scale.
Who should skip one
- Anyone who feels trapped or more anxious under weight. One trial participant left for that reason.[60]
- People with possible sleep apnea. Loud snoring, gasping and stop-start breathing are reasons to see a doctor first.[19]
- Young children, or anyone who could not easily move the blanket off themselves.
Long-running insomnia deserves a proper assessment before any purchase.[3] For the wider picture of bedtime trends, see our sleepmaxxing roundup.
The study behind the product, every time.
Our free list reads the research behind sleep products so you do not have to.
Sources
- Ekholm et al., 2020. A randomized controlled study of weighted chain blankets for insomnia in psychiatric disorders. Journal of Clinical Sleep Medicine.
- NHLBI, 2025. Sleep Apnea: Symptoms. National Heart, Lung, and Blood Institute (NIH).
- NHLBI, 2022. Insomnia: Diagnosis. National Heart, Lung, and Blood Institute (NIH).
This article is educational and isn’t medical advice. It was written and checked by the UNWIRE™ editorial team; no clinician has reviewed it yet. UNWIRE™ is a nutrition company, and this article does not describe any product.
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