Key points are not available for this paper at this time.
Serum melatonin concentration in early morning during the menstrual cycle, studied in five healthy women, showed that melatonin was elevated at the time of menstrual bleeding and had its nadir at the time of ovulation. It is possible that melatonin is involved in the regulation of the menstrual cycling in humans.
Wetterberg et al. (Thu,) studied this question.