Oxytocin is a hormone that causes the uterus to contract. It is used to induce labour, strengthen contractions during childbirth, and to control bleeding after childbirth.
Oxytocin also appears to play a key role in social behaviour and social understanding.
For example, it helps to regulate sexual behaviour, mother-infant and adult-adult pair-bond formation and social memory/recognition. It has also been implicated in repetitive behaviours and stress reactivity.
Some people believe that individuals with autism, and a wide range of other conditions, have abnormal levels of oxytocin.
They also believe that some of the problems faced by those individuals can be treated by taking oxytocin, either by injecting or by inhaling it.