In a small study of healthy adults aged 55 and older, 5 mg of melatonin increased total sleep time compared to a placebo.
Researchers from Brigham and Women’s Hospital conducted the study in 24 healthy, older adults to evaluate whether a high-dose or a low-dose melatonin supplement could improve sleep. The team found that the higher dose had a significant impact, increasing total sleep time compared to placebo by more than 15 minutes for nighttime sleep and by half an hour for daytime sleep. Results are published in The Journal of Pineal Research.
“Sleep deficiency becomes more common as people age, and, given the drawbacks to many prescription sleep aids, many older adults report taking melatonin,” said senior author Charles Czeisler, chief of the Brigham’s Division of Sleep and Circadian Disorders. “But we’ve had little evidence on the effects of melatonin on the sleep health of older adults. Our study provides new evidence and insight, and points to the importance of considering dosage and timing when it comes to the effects of supplements like melatonin, especially in older people.”
The body naturally produces the hormone melatonin, which helps regulate a person’s sleep-wake cycle with night and day. Melatonin levels peak at night. But among older people, levels of the hormone are often lower. Exogenous melatonin is sold over the counter and can be taken before bedtime as a dietary supplement, usually in the form of a pill or capsule.
To rigorously evaluate the effects of melatonin supplements, the study’s authors focused on healthy, older adults with no history of major sleep complaints. All potential participants were screened for sleep disorders. The study included 24 participants (13 women, 11 men) between the ages of 55 and 78.