Background: Sexual function in women may be affected by their menstrual cycle. Lack of sexual drive is a deficiency or absence of sexual fantasies and desire for sexual activity. This study aims at determining the changes in sexual desire during the menstrual cycle and those associated with premenstrual syndrome (PMS) and evaluates sexual desire during the menstrual cycle and the associated changes with PMS.

Methods: The sample for this cross-sectional study includes 150 women employed in factories in Tehran. The instruments for data collection were questionnaires and journals of premenstrual experiences.

Results: Analysis of the data showed that the mean age of the subjects was 31 years )standard deviation = 8.46(. The most frequent decrease in sexual desire was during the week prior to the start of menstrual bleeding (27.3%) and the least frequent was from the end of bleeding to one week before the next period of menstrual bleeding (5.3%). In 24.7% of the cases, an increase in sexual desire occurred during the middle of the menstrual cycle and 27.3% during the course of menstrual bleeding. Moreover, 10.7% of the subjects had an increase in sexual desire during the week before bleeding. Furthermore, a positive correlation was found between changes in sexual desire and PMS (p<0.001). In addition, a positive correlation was found between changes in sexual desire and breast tenderness, joint and muscle pain.

Conclusions: The sexual desire of women, with or without PMS, changes during the menstrual cycle. The greatest decrease in sexual desire occurs during the first week before menstrual bleeding in women with PMS. Such information can greatly help toward understanding and treatment in sexual therapy for couples.