No wonder we get addicted to romance. It's a natural painkiller.
Arthur Aron, a SUNY Stonybrook neuroscientist who studies love, and Sean Mackey, the chief of Stanford University School of Medicine's pain management center teamed up on a study that found that both love and pain activate the same brain circuits.
Students in love felt less pain while staring at a picture of their significant others. In addition, love acted through the same brain pathway as several strong painkillers and addictive drugs such as heroin and cocaine.
It's important to note that these were college students who had been "passionately in love" for less than nine months, so they were definitely in the romantic, dopamine-fueled state, not the oxytocin-supported committed love state.
BTW, London's Daily Express has a bit more on this, as well as other ways that love and relationship make us healthier and happier.