3Drowsiness
One of the most common side effects of melatonin is drowsiness. It is quite like a hangover. If you take melatonin to sleep well at night, it would make you feel tired or drowsy the next day. In other words, the sleep effect would hang around a bit longer. This may be because you took too much and the body could not process melatonin quickly during the night. Try to make an adjustment to see if the side effect goes away. In case it affects your daily lives by reducing alertness or concentration, it is better to consult your doctor and change to another supplement. Keep in mind that some drugs would intensity drowsiness, such as selective serotonin reuptake inhibitors and depressants. [4]
