|Why men fall asleep straight afterwards.|
Research in the journal Neuroscience and Behavioural Reviews in 2012 has explained the sleeping-pill like effect making love has on men. Brain scans showed the pre-frontal cortex, the area associated with consciousness, alertness and mental activity, 'switches off' after an orgasm.
Other research has shown that in men an orgasm's tension-relieving effects are like taking 2mg of diazepam (a sedative). 'This explains why men want to sleep after making love,' says Dr Ghosh. And hormones released in orgasm - melatonin, oxytocin and vasopressin - are also all associated with sleep.