Agomelatin is an atypical antidepressant drug approved in a number of European countries for treatment of major depressive disorder. Agomelatin is a melatonin receptor agonist and, as such, shares some pharmacological properties with related compounds.

Agomelatin is structurally similar to melatonin, a naturally-occurring compound involved in the regulation of sleep. Melatonin and its analogs, such as agomelatin, are thought to modulate neurotransmission by acting as agonists at melatonin receptors, MT1 and MT2. The exact mechanism by which agomelatin and other melatonin agonists act as antidepressants is unknown.

Agomelatin has shown antidepressant effect in animal models of depression and in clinical trials in humans. Agomelatin is the first melatonin agonist to be shown effective in the treatment of major depression in humans.

Agomelatin is commercially available in Europe and other countries as Valdoxan and in India as Melitor.