most likely to occur during a woman's brief fertile period, evolutionary theories suggest that men possess adaptations designed to maximize their reproductive success during this period. Women's fertility shapes male mating behaviour, many studies have shown that being exposed to the scent of women's fertility led men to display greater implicit accessibility to mating-related concepts, males also judged the odours of women during the follicular phase as more pleasant and 'sexy' than odours during the luteal (non-ovulatory) phase. Olfaction, therefore, transmits information relevant to human mate selection, through which men are capable of detecting shifts in women's fertility. There is now also considerable evidence from psychological studies that women's preferences for various male traits change throughout the menstrual cycle. Hormonal fluctuation across the menstrual cycle explains temporal variation in women's judgment of the attractiveness of members of the opposite sex. This is due to the psychological processes that shape the formation and maintenance of human romantic relationships, which are influenced by variation in hormonal levels. Due to their high hormone content, oral contraceptives have the potential to alter women's partner preference for a range of male traits, which could have important consequences on sexual relationships, as it alters women's attraction to their partner and, potentially, to other men. If a woman's use of oral contraceptives is congruent, meaning she was using oral contraceptives when she met her partner, her current preference will more closely match the preference that shaped her partner choice in the first place, and the desire is higher than that of a woman whose use of oral contraceptives is incongruent. The resulting factor is that women's partner preferences are influenced by oral contraceptives use, meaning that attraction towards an existing partner changes over time if a woman initiates or discontinues oral contraceptive use. Studies have shown that men are more attracted to women when they are more fertile and/or on their menstrual cycle. Women gave samples of when they were fertile and less fertile. The men in the study would smell and choose which sample between the two they were more attracted to. Women give off a more favorable smell the more fertile they are; in other words, men notice this and choose the more fertile sample rather than the less fertile sample. Body odour as a cue for ovulation In contrast to previous results reported in the literature, it has also been found that odours perceived