A new study by scientists at the University of Pisa measured the hormones in the blood of volunteers. Those newly in love showed high levels of nerve growth factor called neurotrophin. People who had been coupled for two years or so had normal levels of neurotrophin, but higher levels of oxytocin, the cuddle hormone.
Donatella Marazziti, who led the research team, said: "If lovers swear their feelings to be ever-lasting, the hormones tell a different story."
BBCANews.com has the best story, with comment from Dr. Petra Boynton of the British Psychological Society pointing out that committed love isn't a lesser state.
Dr Boynton said: "This feeds into a 1970s view that when you meet it's all sparky, and then it's a downward trajectory to cuddles - which is seen as a negative.
"It is suggesting that what happens first is the best bit - and that isn't true."