I found this here: http://www.medscape.com/viewarticle/406718_2
> "Like pharmaceutical monoamine oxidase (MAO) inhibitors, estrogen
> reduces MAO activity, resulting in higher levels of both catecholamines
> and serotonin in the brain.[40] Estrogen also increases opioid and
> endorphin production by the hypothalamus.[41]"
>
>
Sorry, forgot the pointer. ren