Does Melatonin Cause Nightmares?


Melatonin CAN cause nightmares.

More Info: One of the side effects of taking melatonin supplements can be vivid dreams or nightmares.

What Is Melatonin?

Melatonin is a hormone produced in the brain that regulates the body’s internal clock called the circadian rhythm.  The circadian rhythm follows a 24-hour cycle affecting physical and behavioral changes based on darkness and light.  The body produces more melatonin when it is dark, less when it is light.  It also controls the release of female reproductive hormones.  Some people take melatonin supplements in an attempt to relieve insomnia.

Additional Side Effects of Melatonin Supplements

In addition to causing vivid dreams or nightmares, possible side effect of taking melatonin are drowsiness during the day, headache, dizziness, stomach cramps, irritability, interference with fertility, decreased sperm count, and decreased libido.  It can also worsen the symptoms of depression.

Important to Consult Your Physician

Because melatonin interacts with several prescription medications, you should always consult your physician prior to taking supplements.



“Melatonin.” University of Maryland Medical Center | Home. N.p., n.d. Web. 11 July 2012. <>.

“Circadian Rhythms Fact Sheet – National Institute of General Medical Sciences.” NIGMS Home – National Institute of General Medical Sciences. N.p., n.d. Web. 11 July 2012. < >