The researchers said that many participants have experienced better sleep quality after getting exposed to the scent of their partners, though their partners were not present physically.
"Our findings provide new evidence that merely sleeping with a partner's scent improves sleep efficiency. Our participants had an average sleep efficiency improvement of more than two per cent," said Marlise Hofer, lead author of the study said.
"We saw an effect similar in size to what has been reported from taking oral melatonin supplementsâ€”often used as a sleep aid," Marlise added.
155 participants took part in the study and all of them were given two identical t-shirts which the participants have to be used as the pillowcases.
Out of the two t-shirts, one t-shirt has been used by their romantic partner, while the other t-shirt was either worn by the stranger or was clean.