They technically do regulate, and honestly are still likely a godsend to women with extreme irregularities/acne/cramping. Birth control is a double edged sword. I haven't looked into pair bonding aspects of it, as that seems like it would be more impacted by oxytocin (which is fucked during cesarean procedures iirc-- but that's birth and I'm getting OT). I would garner the rates of use with antidepressant and anxiolytic meds could possibly have an effect as well. It can definitely dink up mood though, among a laundry list of other bullshit that can lead to problems in relationships.