Research of the past has suggested that women having a preference for masculine faces was largely related to their hormones. Findings from a 2013 study, suggested that women who were on the pill were attracted to less masculine faces compared to women who did not use hormonal forms of contraception. On the same note, another study seemed to find that women were most likely to lust after masculine men during the fertile phase of their menstrual cycle.

However, a new study of nearly 600 women has provided strong evidence that perceptions of male attractiveness do not vary according to the hormone levels of women. The paper titled "No compelling evidence that preferences for facial masculinity track changes in women’s hormonal status" was published in the journal Psychological Science on April 30.

For the study, 584 heterosexual women were recruited to participate in a series of test sessions on a weekly basis. At each session, they were asked to report their relationship status and whether they were currently using hormonal contraceptives. This took place for five weeks, followed by a second block of testing after six months and a third block after two years.

The participants also provided saliva samples and completed two face-preference tests. While the former was to measure hormone levels, the latter was to assess their attraction based on two situations: Whether they were looking for a man for the purpose of a short-term fling or a long-term relationship.

The women were shown ten pairs of randomized male faces and asked to pick the one they were attracted to the most, and also rate how attractive each face was. Faces were slightly altered to look more masculine or feminine by changing features such as the eyebrows, jawline, cheekbones etc.

The results revealed that their preferences did not vary according to their levels of fertility-related hormones, such as estradiol and progesterone.

"We found no evidence that changes in hormone levels influence the type of men women find attractive," said lead researcher Benedict C. Jones from the University of Glasgow in Scotland.

According to the authors, this was the largest longitudinal study of the hormonal correlates of women's preferences for facial masculinity. This allowed them to avoid the limitations of previous studies that often examined small samples of women.

The female participants generally rated the masculinized faces as more attractive than the feminized faces. However, one finding the study could replicate was that straight women, on average, were most likely to pick more masculine faces when looking for a short-term fling.

The main take away from this study, Jones said, was that oral contraceptive does not affect women's preferences for masculine faces. 

"There has been increasing concern that the birth control pill might disrupt romantic relationships by altering women's mate preferences, but our findings do not provide evidence of this," Jones stated. 

While the study was noted for its scope, it still had limitations regarding the diversity of participants. All the women in the study were white, and so were all the male faces used in the test. The researchers wanted to continue investigating if other fertility-related differences hold up in larger studies.