The “deep touch pressure” effect of weighted blankets has been studied for decades as an answer to helping relieve anxiety, and as research progresses, it’s now being tapped for insomnia, reports Well+Good.

According to psychotherapist Ginnie Love Thompson, PhD: “When someone’s upset and you hug them, the hug not only offers emotional security, but research has also proven firm contact of the physical sensory produces an effect that calms the parasympathetic nervous system.”

It does so by reducing the body’s secretion of the stress hormone cortisol, which is also responsible for lessened serotonin and dopamine. But buying a weighted blanket isn’t as simple as just clicking add to cart. Commonly weighted blankets range between four to 30 pounds, and when choosing one, you should plan for it to account for about 7 to twelve percent of your body weight.