They said hormone treatments such as tibolone (Livial) which used male sex hormones called androgens, rather than female hormones, were more successful in increasing libido.

BBC: Sex a turn-off for many UK women

The men in these couples, she discovered, exhibited significant changes in their levels of cortisol, testosterone (the principal male sex hormone, and thus in some sense the masculine equivalent of estradiol) and prolactin over the courses of their partners' pregnancies.

ECONOMIST: Hormones and fatherhood