Sexual dysfunction and diminished sexual desire are common complaints among midlife women. These sexual difficulties may relate to the ovarian hormone changes that occur during the menopause transition (i.e., “perimenopause”). Levels of estradiol fluctuate during this period, at times reaching very low levels, which may result in physiological effects that, in turn, impact sexual function and desire. However, the extent to which perimenopausal changes in libido are directly related to hormone shifts remains unclear. Since the menopause transition is also associated with an increased risk of depressive symptoms, perimenopausal mood changes may also contribute to perimenopausal changes in libido. This study aimed to examine the relative contributions of within-person changes in weekly depressive mood and ovarian hormone levels on weekly libido. Fifteen perimenopausal women reporting clinically elevated levels of depressive symptoms were recruited. Once a week for eight weeks, they completed a survey assessing depressive mood and sexual desire and provided a urine sample for the measurement of the urinary metabolites of estradiol and progesterone, resulting in a total of 120 hormone-survey pairs. Multilevel modelling examining the within-person effects of hormones and depressive mood on sexual desire revealed that while with-person weekly changes in depressive symptoms significantly impacted sexual desire, weekly changes in ovarian hormones did not. In the future, our team will recruit additional participants to examine these relationships in a larger sample as well as investigate potential moderators in the relationship between hormone changes and sexual desire, such as prior history of sexual dysfunction.