Fig. 3.

Progesterone levels increase in response to cold pressor stress during the follicular phase of the menstrual cycle. Progesterone levels during the stress and control session at Baseline and 42m-post-stress. A significant stress session × sample time point interaction is indicated by the top line. A significant difference between control and stress session during the 42m-post-stress sample time point is also indicated. **: p < .01, *: p < .05.