One of the main types of oral contraceptive high in the hormone progesterone was found to boost libido. But this effect only occurred if the woman felt highly committed to her partner.
The same marked effect was not found in the other main type of pill, which also contains the hormone oestrogen. The results suggest that how often women have sex is linked to loyalty to their partner. But the type of hormone most prominent also plays a key role, whether produced naturally or synthetically in the form of oral contraceptive.
The hormones in contraceptives work by mimicking either of the two main phases of the menstrual cycle. One stage is when a high level of oestrogen is dominant during ovulation – the other occurs afterwards when sex is no longer about reproduction and progesterone kicks in.
It is suggested that during this period, described as a period of ‘extended sexuality’ a woman is more likely to engage in ‘pair-bonding’ rather than seeking to have a baby. And a woman is more likely to want to do so with a man she feels strongly attracted and committed to, the authors suggest.
The research was carried out on around 400 young Norwegian women aged between 18 and 30. Writing in the journal Evolution and Human Behaviour, psychologists from the Norwegian University of Science and Technology say the findings may help women choose which pill to take.
Channa Jayasena, a lecturer in reproductive endocrinology at Imperial College London, said women should still principally discuss their choice of birth control pill with their GP.
© Daily Mail