Melatonin agonists and insomnia

Expert Rev Neurother. 2010 Feb;10(2):305-18. doi: 10.1586/ern.10.1.


The ability of melatonin to shift biological rhythms is well known. As a result, melatonin has been used in the treatment of various circadian rhythm sleep disorders, such as advanced and delayed sleep phase disorders, jet lag and shiftwork disorder. The current evidence for melatonin being efficacious in the treatment of primary insomnia is less compelling. The development of agents that are selective for melatonin receptors provides opportunity to further elucidate the actions of melatonin and its receptors and to develop novel treatments for specific types of sleep disorders. The agonists reviewed here - ramelteon, tasimelteon and agomelatine - all appear to be efficacious in the treatment of circadian rhythm sleep disorders and some types of insomnia. However, further studies are required to understand the mechanisms of action, particularly for insomnia. Clinical application of the agonists requires a good understanding of their phase-dependent properties. Long-term effects of melatonin should be evaluated in large-scale, independent randomized controlled trials.

Publication types

  • Review

MeSH terms

  • Acetamides / pharmacology
  • Animals
  • Benzofurans / pharmacology
  • Circadian Rhythm / drug effects
  • Cyclopropanes / pharmacology
  • Humans
  • Hypnotics and Sedatives / pharmacology*
  • Indenes / pharmacology
  • Melatonin / agonists*
  • Sleep Initiation and Maintenance Disorders / drug therapy*
  • Sleep Initiation and Maintenance Disorders / physiopathology


  • Acetamides
  • Benzofurans
  • Cyclopropanes
  • Hypnotics and Sedatives
  • Indenes
  • agomelatine
  • ramelteon
  • Melatonin
  • tasimelteon