A key goal of SWAN is to increase our understanding of hormonal patterns during midlife and their relationships to menstrual cycle changes. To do this we initiated the Daily Hormone Study. 90 women in the Pittsburgh area and 900 across all SWAN sites began participation in the Daily Hormone Study in 1997. Women who are still menstruating, have an intact uterus and at least one ovary, are not currently pregnant, and are not using any sex steroid treatments continue to participate.

Participants in the DHS are given urine collection kits, a freezer to store samples, and a DHS Diary. It is extremely important that participants collect samples every day and record pertinent information in their Diary. Participants will be instructions on how collection protocols will work.