Pharmacodynamics of progesterone women, this effect being the result of suppression of the mid-cycle surge in gonadotropin secretion, is 300 mg/day. However, this figure is based on limited clinical data. Conversely, treatment with a high dosage of oral progesterone of 100 mg four times per day (or 400 mg/day total) in men for 10 days that resulted in approximately mid-luteal phase levels of progesterone (7.9–9.4 ng/mL; measured by ) did not cause any change in testosterone levels, suggesting that progesterone has little or no antigonadotropic effect in males at typical clinical dosages. In addition, a study found that administration of 1,000 mg/day oral
Menstrual synchrony Menstrual synchrony Menstrual synchrony, also called the McClintock effect, is an alleged process whereby women who begin living together in close proximity experience their menstrual cycle onsets (the onset of menstruation or menses) becoming more synchronized together in time than when previously living apart. "For example, the distribution of onsets of seven female lifeguards was scattered at the beginning of the summer, but after 3 months spent together, the onset of all seven cycles fell within a 4-day period." Martha McClintock's 1971 paper, published in "Nature", says that menstrual cycle synchronization happens when the menstrual cycle onsets of two or