“We’ve identified the molecules that we believe form the essential gears of the 24-hour clock,” says researcher Steven Reppert, who is a professor of pediatrics at Harvard-affiliated Massachusetts General Hospital. “This understanding could lead to quicker and more efficient ways to reset the clocks of those suffering from jet lag or genetic sleep disorders, or those trying to adjust to shift work.” That’s good news for those whose sleep cycles are disrupted. Shift and travel adjustments can be made by exposure to illumination from so-called “light boxes,” but such resetting is time-consuming. And as natural sleep potions, melatonin supplements have not lived up to their hype. However, the past few years have seen an explosion of research into the molecular ticking and resetting of inborn clocks. Reppert and colleagues also announced the discovery of a previously unknown feedback loop in the clocks of mammals that automatically switches sleep and wakefulness genes on and off as needed.