Nonsteroidal anti-inflammatory drugs are a family of pain relievers that includes aspirin, ibuprofen and indomethacin. Volunteers who took just one normal dose of aspirin or ibuprofen in the evening had as much as a 75 percent reduction in melatonin levels.

Anti-Anxiety Drugs and Sleep Aids

At least two widely prescribed anti-anxiety drugs, diazepam (Valium) and alprazolam (Xanax), inhibit melatonin production. Both of these medications belong to a family of drugs called benzodiazepines (which we discussed in more detail in Chapter 8).


Many antidepressant drugs stimulate melatonin production. But the most popular antidepressant drug, fluoxetine (Prozac), which has annual sales in the United States of more than a billion dollars, could lower your melatonin levels.A study published in The British Journal of Psychiatry in 1995 reports that depressed patients who took fluoxetine had significantly lower nocturnal melatonin levels after one week of use. Subjects who were not depressed who took fluoxetine also had lower melatonin levels after one week, and their levels declined even further after six weeks of use.


Caffeine has been used for centuries to increase alertness, but we learned oly recently that it achieves this end, in part, by blocking the production of melatonin. Given caffeine’s reputation for disturbing sleep, it’s remarkable that no one explored the caffeine-melatonin connection until 1994. Dr. Kenneth Wright, Jr., and his colleagues at Bowling Green State University measured the melatonin levels of a group of individuals who volunteered to stay awake for two consecutive days. Some were given a placebo and others were given 200 milligrams of caffeine, which is equivalent to two strong cups of coffee. Compared with the placebo, caffeine caused a significant reduction in their melatonin levels.


At least two studies have suggested that people who smoke cigaret8tes have lower nighttime melatonin levels than people who don’t. One of the studies, published n 1994, reported that “all the smokers had lower melatonin levels than non-smokers. The relation between smoking and melatonin concentrations needs to be further studied.”


A 1993 study showed that volunteers who drank the equivalent of one or two glasses of wine at seven o’clock in the evening had 41 percent less melatonin at midnight compared with nights when they were given a nonalcoholic drink. When they were given higher doses of alcohol, they had low melatonin levels until the early hours of the morning.

Could this be why alcohol disrupts sleep? Although alcohol may ease anxiety and help you fal;l asleep, it can produce a rebound effect several hours later, leaving you wide awake and staring at the clock. Studies have shown that alcohol decreases both REM sleep and delta sleep, which is the most restorative part of the sleep cycle. It also increases the number and duration of awakenings throughout the night.

Excerpted from Melatonin: Your Body’s Natural Wonder Drug, Chapter 15, pages 182-191.