In the mood?
Did your girlfriend turn a cold shoulder the last time you made a move? Or maybe you had more luck turning her on? If only there were a way to measure her hormone levels, then maybe you’d know when not to bother, and when you’d be in for a good time.
That’s because a woman’s monthly changes in hormone levels are linked to how interested she is in sex, the new study found. Scientists asked 43 students to keep a daily diary recording how much they were in a sexy mood, and whether they had sex. The women also took daily saliva samples which were tested for levels of the hormones estrogen, progesterone, and testosterone.
The result was what you might expect. Women want sex the most when they’re most likely to get pregnant. Sexual desire is highest in the middle of a woman’s menstrual cycle, right around the time of ovulation. After that, a woman may be less responsive to her partner’s advances since sexual desire drops to its lowest shortly after ovulation.
The hormone that makes her want it
Hormones, it turns out, are behind these monthly highs and lows in sex drive. Estrogen has a positive effect on desire – it’s at its highest right before ovulation, when the women in the study were most often in the mood to get it on.
Progesterone, on the other hand, is libido’s arch enemy. This hormone acts like a sex drive stop signal, and is responsible for the period after ovulation when women are less likely to want sex.
Testosterone is the hormone people think of as boosting all things ‘manly’ – including libido – either in men or women. But in fact testosterone doesn’t seem to have an effect on women’s sexual desire in the natural cycle.
This study was the first to prove that estrogen and progesterone are linked to the monthly changes in a woman’s sex drive, something which scientists have known happens in other primates like rhesus monkeys.
More to lust than hormones
But a high libido is not a simple question of more estrogen and less progesterone – the study found no difference in the average levels of these hormones between the women who had the highest sex drives and those less interested in sex.
There are many factors that affect a woman’s libido. Both desire and sex shot up on weekends for the women in this study, regardless of hormone levels. Something as practical has having time to enjoy sex with a partner instead of cramming for finals can affect sex drive, the study also showed.
Fertility
Why does sexual desire increase around ovulation? At first, the answer seems pretty obvious – to increase a woman’s chances of getting pregnant when her egg is released. But if it were just a question of upping the chances of fertilisation, why wouldn’t women have a high sex drive 24/7?
In the past, having nothing but sex on the brain might not have been in a woman’s best interests. Both during her monthly cycle and during longer periods of low fertility, for example when there was less food available, it would have made more sense for a woman to be thinking about things other than sex, like looking for food, or taking care of her children. So it’s possible that the hormones estrogen and progesterone evolved to have roles in sex drive that are linked to fertility, according to the study’s authors.
*To protect the identity, names have been changed and the person/s in the picture is/are models.
Do you notice your sex drive changes over the month? Or your girlfriend's sex drive? Tell us your experiences here or on Facebook.