linguistic:paraphrasing, information:classification, structural:reformatting, linguistic:voice_change
Sexual attractiveness and function

COCPs may increase natural vaginal lubrication, while some women experience decreased lubrication.

In 2004, the Proceedings of the Royal Society B: Biological Sciences published a study where pairs of digital photographs of the faces of 48 women at Newcastle University and Charles University between the ages 19 and 33 who were not taking hormonal contraceptives during the study were photographed in the late follicular and early mid-luteal phases of their menstrual cycles and the photographs were then rated by 261 blinded subjects (130 male and 131 female) at their respective universities who compared the facial attractiveness of each photographed woman in their photograph pairs, and found that the subjects perceived the late follicular phase images of the photographed women as being more attractive than the luteal phase images by more than expected by random chance.

In 2007, Evolution and Human Behavior published a study where 18 professional lap dancers recorded their menstrual cycles, work shifts, and tip earnings at gentlemen's clubs for 60 days that found by a mixed model analysis of 296 work shifts (or approximately 5,300 lap dances) that the 11 dancers with normal menstrual cycles earned US$ 335 per 5-hour shift during the late follicular phase and at ovulation, US$260 per shift during the luteal phase, and US$185 per shift during menstruation, while the 7 dancers using hormonal contraceptives showed no earnings peak during the late follicular phase and at ovulation. In 2008, Evolution and Human Behavior published a study where the voices of 51 female students at the State University of New York at Albany were recorded with the women counting from 1 to 10 at four different points in their menstrual cycles were rated by blinded subjects who listened to the recordings to be more attractive at the points of the menstrual cycle with higher probabilities of conception, while the ratings of the voices of the women who were taking hormonal contraceptives showed no variation over the menstrual cycle in attractiveness.