Study, 1988
What happens when women take a drug that blocks progesterone during the second half of their menstrual cycle?
The drug triggered menstruation in 43% of women and caused a temperature drop in 56%. It also changed mood in 23% and made major changes to the womb lining.
What they did
Thirty women took RU486 (dose 5 to 200 mg, one single dose) during the first half of the luteal phase (the second half of the cycle). Doctors examined tissue from the womb lining under the microscope and noted changes in temperature, menstruation, hormone response, and mood over the following days.
What they found
The drug stopped normal womb lining activity, caused cell death and blood vessel changes, and increased cell growth in some areas. A temperature drop happened in 56%, menstrual bleeding started in 43%, hormone changes happened in 24%, mood changed in 23%, and thirst increased in 3%. Most changes happened around 48 hours after taking the drug.
What it means for you
Blocking progesterone has wide-ranging effects on the body, including triggering menstruation and changing mood. This shows progesterone plays an important role in controlling menstruation and mood. The study used a single dose, so we don't know what happens with repeated doses.
30
women
56%
temperature drop
43%
menstrual induction
About the study
- Original title
- The effects of progesterone receptor blockade in the luteal phase of normal fertile women
- Authors
- Li TC, Dockery P, Thomas P et al.
- Journal
- Fertility and sterility
- Year
- 1988
- Study design
- Study
- Participants
- 30
- What was tested
- RU486 (dose 5 to 200 mg, single dose) during first half of luteal phase
- Open access
- Yes
- Read the paper
- doi.org/10.1016/s0015-0282(16)60307-2