Why are the major sleep societies hesitant to endorse melatonin for run-of-the-mill insomnia?

The American Sleep Association and National Sleep Foundation cite conflicting evidence about efficacy while cautiously suggesting that it might help some people. The American Academy of Sleep Medicine (AASM) actually advises clinicians against recommending melatonin, weighing the overall evidence as “weakly against” its efficacy.

Because melatonin has immune-enhancing properties, there is also some debate about its safety in patients with autoimmune diseases. Although recent discussion has largely sided with its safety in this context, there are still a few cautionary voices.

Rüdiger Hardeland, PhD, from the University of Göttingen, who has studied melatonin and is now a retired zoologist, is one of them. “Melatonin can stimulate the release of proinflammatory cytokines and other mediators,” he said, explaining that studies linking endogenous melatonin levels to symptoms of rheumatoid arthritis (RA) have convinced some clinicians that melatonin supplementation may not be advisable in patients with RA. “For me, this finding has to be seen as a caveat concerning all autoimmune diseases,” he cautioned. Indeed, the Arthritis Foundation advises against melatonin for patients with autoimmune disease.