Theory 30/Menstrual cycle/Termination phase
Termination Is Luteolysis
The claim
The cycle ends when luteolysis reduces progesterone below a threshold relative to endometrial support, so the end is a ratio rather than a time.
01Mechanism
Withdrawal of progesterone triggers shedding; the ratio sets the threshold.
02Prediction
Termination should track the ratio.
03Refutation
Termination tracking cycle day would remove luteolysis.