Steven W. Lockley, Ph.D.

Co-Founder & Chief Scientist

Dr. Steven Lockley is the Co-founder and Chief Scientist at Timeshifter. Before joining Timeshifter full-time in 2024, he served as a Neuroscientist at Brigham and Women’s Hospital and as an Associate Professor of Medicine in the Division of Sleep Medicine at Harvard Medical School, where he was on the faculty for over 20 years. With more than 30 years of research experience, Dr. Lockley is a globally recognized authority on circadian rhythms and sleep. He has helped numerous organizations and individuals manage jet lag, shift work disorder, and optimize performance. Dr. Lockley has applied his expertise to guide NASA astronauts and mission controllers, Formula 1 drivers, and elite athletes.

Dr. Lockley is a world-renowned specialist in ways to reset the circadian clock using light or melatonin and its agonists, the only known ways to phase shift circadian rhythms in humans. He has studied the effects of light on the circadian pacemaker extensively including the role of light wavelength, timing, duration and pattern. This work has led to development of ‘smart’ lighting applications designed to improve alertness, safety and productivity in architectural and clinical applications, and he was one of the leading scientists in the development and application of new lighting systems for the International Space Station.

Dr. Lockley has also made major discoveries in the use of melatonin and its agonists to reset circadian rhythms. He was the first person to show that daily melatonin treatment could synchronize the circadian clock of blind people suffering from non-24-hour sleep-wake disorder, which inspired the development of tasimelteon (Hetlioz) for use as a circadian synchronizer in the blind. Dr. Lockley led the resulting clinical trials, and tasimelteon was approved by the FDA as the world’s first drug in a new class of therapies that treat circadian sleep disorders by resetting the circadian clock.

Dr. Lockley also has extensive experience in studying shift work and how to manage it. He has led multiple trials to test interventions to reduce workplace errors and injury, and to measure the impact of circadian disruption, long work hours, sleepiness and sleep disorders on performance and health, including in doctors, nurses, police, firefighters, and industry. His clinical trials have been able to demonstrate a significant impact in important real-world outcomes, including reducing medical errors by 30-36% in US and UK doctors; a 33% reduction in serious medical errors in ICU nurses; a 47% reduction in long-term disability days in firefighters, and a 43% reduction in falls in care home residents.

Dr. Lockley is a highly productive scientist, and has published over 200 original scientific papers, reports, reviews, chapters and editorials, as well as co-editing the first textbook on sleep and health ‘Sleep, health and society: From Aetiology to Public Health’ and co-authoring ‘Sleep: A Very Short Introduction’ from Oxford University Press. His work has been widely reported in numerous press articles including in National Geographic, Time magazine, BBC, New York Times, Wall Street Journal, Financial Times, New Yorker, Scientific American and many others. His research has been funded by NASA and the National Institutes of Health (NIH) among others and he has won a number of awards including the NASA Johnson Space Center Director's Innovation Team Award (as part of the ISS Flexible Lighting Team).