MELATONIN & SLEEP: SCIENCE-BACKED, PLAIN-LANGUAGE GUIDE “Often, better mood follows better sleep.” Melatonin is not a “happiness hormone.” However, sleep quality and circadian stability strongly influence mood. Poor sleep is linked with irritability, increased anxiety, and depressive symptoms. If melatonin improves circadian alignment and sleep, you may feel better indirectly—not because it is a mood-elevating drug, but because your body is more synchronized. Some people experience vivid dreams, morning grogginess, or occasional restlessness, which can worsen mood. Individuals with a history of bipolar disorder should be especially cautious and seek specialist advice. If your primary goal is stress/anxiety control, melatonin can be a supportive piece, but not the core solution. Sleep hygiene, daytime activity, sunlight exposure, psychological support, and medical care when needed are more decisive. The best metric for melatonin is: more regular sleep and more refreshed mornings.