Bright Light vs Melatonin vs Placebo in Shift Workers: Randomized Field Study
Summary
This randomized, placebo-controlled crossover field trial examined melatonin and bright light as countermeasures to shift-related sleep problems in 17 oil-rig workers on a rotating schedule. Workers received melatonin (3 mg before bed), timed bright-light exposure, or placebo during the first four days of night and day shifts. Melatonin reduced sleepiness during day shifts and increased total sleep by about 15–20 minutes per day. Bright light produced modest improvements in objective sleep during night shifts, but overall effects were limited. Few outcomes reached strong statistical significance, likely due to real-world variability and suboptimal timing.
Why It Matters For Night Shift Workers and Night Owls
This study shows that melatonin and bright light can provide modest benefits when adapting to night work, but they are not stand-alone solutions. Melatonin before daytime sleep may help shift workers fall asleep sooner and gain a small increase in sleep duration, while targeted bright light during night duty can slightly improve alertness. These strategies are most effective when carefully timed and combined with broader measures such as protecting recovery periods and minimizing extended shifts.
Notes
Field conditions; classic comparator trial.