The use of scents to aid sleep goes back to ancient times. In ancient Egypt things such as henna, frankincense, myrrh, cinnamon & cypress were burned to help induce sleep and enhance dreams. In Rome, the use of chamomile was common to help one relax. Fast forward a couple thousand years, and we are seeing growing research exploring the ability of odours to promote sleep.
Thus far, research has mostly focused on lavender, with studies suggesting that exposure to it prior to sleep can:
Scents that are scientifically proven to promote relaxation and improve sleep quality include: