The desirable side effect of melatonin is sleepiness, but other side effects can be present as well. Some people have experienced severe headaches, dizzy spell and abdominal
pain. Sleep behaviors may occur as well, including sleepwalking.
A good night’s sleep is extremely important for proper functioning the following day. Some people who use melatonin may experience sleepiness the day after taking the synthetic hormone. In some cases, confusion and the inability to focus can occur.
The point of using melatonin is to get restful sleep, allowing for a fatigue-free day. Some of the side effects of melatonin lead to the same daytime sleepiness people taking the supplement want to avoid in the first place.