Sleep isn’t just a luxury, it’s a vital process that helps our bodies repair and rejuvenate. Researchers have started to uncover how the quality and timing of sleep can affect more than just how rested we feel—it might also affect the very blueprint of our cells: our DNA.

A new study from Canada found that melatonin, a hormone known for its role in regulating sleep, might help reverse some of the DNA damage caused by years of poor sleep.

Melatonin is produced by the pineal gland in our brains when darkness falls. It signals to our bodies that it’s time to wind down and prepare for sleep. Beyond its sleep-inducing properties, melatonin is also a powerful antioxidant.