This is a clarified version of the Letters to the Editor that appeared in print.
Am Fam Physician. 1998;57(8):1783-1787
to the editor: The New England Journal of Medicine recently published a review article on melatonin.1 In the article, the author reviews most of the published studies on this hormone and concludes, “There is now evidence to support the contention that melatonin has a hypnotic effect in humans. Its administration in doses that raise the serum concentrations to levels that normally occur nocturnally can promote and sustain sleep.”
The October 1, 1997, issue of AFP also had an article regarding melatonin.2 After reviewing some of the literature on this pineal hormone, Dr. Cupp concludes, “Until more is known about this drug, it should be used cautiously, if at all.” Frankly, I didn't see anything in the article that would lead to this kind of overcautious final recommendation. Has melatonin been associated with deaths? With falls and fractures, accidents or loss of memory? Why not recommend the occasional use of melatonin to treat insomnia and jet lag? Millions of Americans safely and effectively use melatonin for this purpose. It's been over three years since it has been available to the public, and no serious side effects have been reported in the medical literature. The same certainly cannot be said about the benzodiazepines.
The public has become more and more interested in natural alternatives to drugs. However, patients are not getting balanced information about these alternatives. As long as some members of the medical establishment try to discredit the use of natural alternatives that may be effective, patients will continue to lose faith in doctors. Patients are getting smarter, and they are recognizing that doctors are sometimes the last people to learn about and accept these natural, alternative forms of therapy. The public is also starting to realize that the medical establishment may not be willing to give a fair opinion about these natural alternatives partly as a result of influence from pharmaceutical companies. If melatonin were to become more popular, what would happen to sales of pharmaceutical hypnotics?
in reply: Dr. Sahelian contends that melatonin has been used safely and effectively by millions of Americans; even so, melatonin has not been objectively evaluated in clinical trials involving large numbers of patients. Furthermore, it is likely that adverse effects of melatonin and other food supplements go unrecognized and are thus unreported, because patients often do not disclose their use of such products to their physicians or other health care professionals.1
In addition to the adverse effects outlined in the article, a psychotic episode temporally associated with the use of melatonin was recently reported.2 The patient who experienced this adverse reaction was also taking fluoxetine, which further indicates the potential for interactions between drugs and food supplements.
Like melatonin, l-tryptophan (a melatonin precursor that caused several deaths) was initially thought to be safe. Although I do not casually dismiss melatonin, I do maintain that, until objective evidence of safety and efficacy is available from properly designed studies, melatonin should be used with caution.