If you work at night or stay awake freq when it is dark, then you are likely to be low in melatonin.
Also, some people sleep regularly, but cycle terribly for any number of reasons, including a partner who snores, or frequent bathroom breaks.
Regardless, it will not cause you harm to take melatonin on a daily basis in order to promote healthy sleep cycle and/or breast cancer cell invasion.
Lisa
www.pinkkitchen.info